CN112696953B

CN112696953B - Preparation method of absorption core of heat dissipation element and heat dissipation element

Info

Publication number: CN112696953B
Application number: CN202011591219.5A
Authority: CN
Inventors: 吴高高; 王和志; 黄国创; 徐莎莎; 方文兵; 林昌伟
Original assignee: AAC Acoustic Technologies Shenzhen Co Ltd; AAC Technologies Holdings Nanjing Co Ltd
Current assignee: AAC Technologies Holdings Shenzhen Co Ltd; AAC Technologies Holdings Nanjing Co Ltd
Priority date: 2020-12-29
Filing date: 2020-12-29
Publication date: 2022-09-30
Anticipated expiration: 2040-12-29
Also published as: CN112696953A

Abstract

The invention relates to the technical field of heat dissipation, and particularly provides a preparation method of an absorption core of a heat dissipation element and the heat dissipation element. The preparation method comprises the following steps: providing an absorbent core body of metal material; soaking the absorbent core body in an alkaline solution; taking out the absorption core body from the alkaline solution to obtain an absorption core; wherein the alkaline solution contains 0.3-3.0 mol/L alkali and 0.1-1.0 mol/L carbonate. The preparation method of the absorption core of the radiating element can obtain the absorption core with the surface having the nano-grade concave-convex structure, and the surface of the concave-convex structure is attached with the basic copper carbonate, so that the capillary acting force and the hydrophilic performance of the absorption core are effectively improved, the wetting performance of the working medium and the absorption core is further effectively improved, and the radiating effect of the radiating element is finally improved.

Description

Preparation method of absorption core of heat dissipation element and heat dissipation element

[ technical field ] A method for producing a semiconductor device

The invention belongs to the technical field of heat dissipation, and particularly relates to a preparation method of an absorption core of a heat dissipation element and the heat dissipation element.

[ background of the invention ]

With the development of 5G technology, electronic components and integrated circuits of mobile phones are continuously developed in the direction of high frequency and high speed, which increases the heat flux density generated during the operation of processors, and the heat productivity is increased rapidly, and the reliability of electronic devices is sensitive to temperature and its sensitivity, so that the reliability of electronic components is threatened by high heat flux.

To solve this problem, a rapid heat dissipation technology for electronic components is a focus of attention. At present, the heat dissipation technology of electronic products such as mobile phones is generally that a heat pipe or a heat-homogenizing plate is placed on a heat source such as a processor and a battery of the mobile phone, and heat generated by the heat source is rapidly led out by means of the flow of a liquid working medium in the heat pipe or the heat-homogenizing plate so as to achieve the purpose of heat dissipation. Therefore, the heat transfer efficiency of the heat pipe or the heat uniforming plate is crucial.

The heat transfer efficiency of the existing heat pipe or heat-homogenizing plate is generally improved by the following methods:

firstly, a nano concave-convex structure is constructed between an evaporation end and a condensation end of a heat pipe workpiece to increase the boiling heat transfer efficiency of the evaporation end, and the nano structure of the condensation end can improve the backflow efficiency of working medium liquid.

Secondly, modifying the working medium to improve the heat exchange coefficient of the working medium and increase the boiling heat transfer efficiency or heat conduction performance of the working medium; or, the surface tension of the working medium is improved, and the contact angle between the working medium and the absorption core is reduced.

Thirdly, the absorption core of the heat dissipation element is subjected to hydrophilic modification, so that water is more easily soaked and spread on the absorption core, and the water absorption rate of the absorption core is improved.

However, the processing of the nanostructure in the first method is complicated, which greatly limits the application of the method in a micro heat pipe. In the second method or the third method, the effect of improving the hydrophilic performance between the absorption core and the water working medium by modifying or simply coating the working medium is limited. In addition, the above method can only improve the wettability of the hydrophilic absorbent core, and hardly improve the capillary force of the absorbent core, and cannot allow the absorbent core with almost no capillary force to be soaked in the working medium.

For this reason, there is a need for a new method for making absorbent cores that solves the above-mentioned problems of the prior art.

[ summary of the invention ]

The invention aims to provide a preparation method of an absorption core of a heat dissipation element, which aims to solve the problems of complex processing, poor capillary action and the like of the existing absorption core nano structure.

In order to achieve the technical goal, the embodiment of the invention adopts the following technical scheme:

a method of making an absorbent core for a heat-dissipating component comprising the steps of:

providing an absorbent core body of metal material;

soaking the absorbent core body in an alkaline solution;

taking out the absorption core body from the alkaline solution to obtain an absorption core;

wherein the alkaline solution contains 0.3-3.0 mol/L of alkali and 0.1-1.0 mol/L of carbonate.

Preferably, the alkaline solution contains 0.5-3.0 mol/L of alkali and 0.3-1.0 mol/L of carbonate.

Preferably, the alkali is selected from at least one of sodium hydroxide and potassium hydroxide, and the carbonate is selected from at least one of sodium carbonate and potassium carbonate.

Preferably, the soaking temperature is 40-80 ℃, and the soaking time is 0.5-4.0 h.

Preferably, the soaking temperature is 40-60 ℃, and the soaking time is 1.0-4.0 h.

Preferably, the absorbent core body is selected from any one of a copper mesh, a copper wire, a copper powder sintered body, a copper foam, and a copper etched capillary structure.

Preferably, basic copper carbonate is attached to the surface of the absorbent core. The second objective of the present invention is to provide a heat dissipation element, which includes a metal shell having an accommodating cavity, an absorption core accommodated in the accommodating cavity, and a heat dissipation working medium filled in the accommodating cavity, wherein the absorption core is prepared by the preparation method of the absorption core of the heat dissipation element.

Preferably, the surface of the absorbent core has a nano-scale concave-convex structure.

Preferably, the absorption core is a copper absorption core, and basic copper carbonate is attached to the surface of the concave-convex structure.

The invention has the beneficial effects that:

compared with the prior art, the preparation method of the absorption core of the radiating element provided by the invention can form a nano-scale concave-convex structure on the surface of the absorption core body, so that the capillary force is enhanced, and the radiating effect of the radiating element is improved.

Under the condition that the absorption core body is made of copper, basic copper carbonate can be attached to the concave-convex structure on the surface of the absorption core body, and the basic copper carbonate has hydrophilic performance, so that the absorption core has good capillary action force, the wettability of a heat dissipation working medium and the absorption core is effectively improved, and the heat dissipation effect of the heat dissipation element is finally improved. In addition, the preparation method of the invention has simple process, and can efficiently obtain the absorption core with the surface having the nano-grade concave-convex structure.

[ description of the drawings ]

FIG. 1 is a schematic flow chart of a method of making an absorbent core provided by the present invention;

fig. 2 is a schematic perspective view of a heat dissipation element according to the present invention;

FIG. 3 is a schematic cross-sectional view of the heat dissipation element of FIG. 2 taken along line A-A;

fig. 4 is an exploded view of the heat dissipation device shown in fig. 2;

illustration of the drawings:

100. a heat dissipating element;

1. an absorbent core;

2. a metal housing; 21. a first housing; 211. a bottom wall; 212. a side wall; 213. a convex column; 22. a second housing; 10. an accommodating chamber;

200. an evaporation end; 300. and a condensation end.

[ detailed description ] embodiments

The invention is further described with reference to the following figures and embodiments. It is to be understood that the described embodiments are merely a few embodiments of the invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that all directional indicators (such as up, down, left, right, front, and rear … …) in the embodiment of the present invention are only used to explain the relative position relationship between the components, the motion situation, etc. in a specific posture, and if the specific posture is changed, the directional indicator is changed accordingly.

It will also be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present.

The embodiment of the invention provides a preparation method of an absorption core of a heat dissipation element.

Referring to fig. 1, the specific process flow includes the following steps:

(1) providing an absorption core body made of metal;

the metal absorbent core body is a copper absorbent core body, and may be selected from any one of copper absorbent core bodies such as copper mesh, copper wire, copper powder sintered body, copper foam, copper etched capillary structure, etc. The absorption core body can be pretreated before soaking, so that the surface of the absorption core body is clean and dry, and other impurities are prevented from being introduced to react with an alkaline solution or the concentration of each component in the alkaline solution is reduced.

(2) Soaking the absorption core body in an alkaline solution;

wherein the alkaline solution contains 0.3-3.0 mol/L alkali and 0.1-1.0 mol/L carbonate.

Preferably, the alkaline solution contains 0.5-3.0 mol/L alkali and 0.3-1.0 mol/L carbonate.

In the alkaline solution, the alkali is selected from at least one of sodium hydroxide and potassium hydroxide, and the carbonate is selected from at least one of sodium carbonate and potassium carbonate.

The soaking temperature is 40-80 ℃, and the soaking time is 0.5-4.0 h.

Further, the soaking temperature is 40-60 ℃, and the soaking time is 1.0-4.0 h.

(3) Taking out the absorption core body from the alkaline solution to obtain an absorption core;

in the actual preparation process, after the absorption core body is soaked by the alkaline solution, the step of cleaning the soaked absorption core body by deionized water can be further included, and the alkaline solution remained on the surface can be removed by cleaning with deionized water. Or, dilute sulfuric acid can be used for soaking the absorption core body taken out from the alkaline solution at room temperature, the dilute sulfuric acid can neutralize the alkaline solution remained on the surface and can also elute basic copper carbonate attached to the surface of the absorption core, and after the dilute sulfuric acid is treated, deionized water is also used for further cleaning the absorption core as necessary.

And, the obtained absorbent core may also be subjected to a drying treatment. Specifically, the temperature of the drying treatment may be natural drying at room temperature. In order to improve the drying efficiency, the drying can be carried out at the drying temperature of 30-100 ℃ or in a drying oven in vacuum, and the liquid residual on the surface only needs to be treated without special requirements.

According to the preparation method, the surface of the obtained absorption core has a nanoscale concave-convex structure, meanwhile, if the absorption core is not soaked in dilute sulfuric acid, basic copper carbonate is attached to the surface of the concave-convex structure, and the existence of the basic copper carbonate can further improve the hydrophilic performance, so that the infiltration effect between the absorption core and the heat dissipation working medium is improved in the capillary action and hydrophilic combination aspect, the temperature difference between the evaporation end and the condensation end of the heat dissipation element is reduced, and the heat dissipation effect of the heat dissipation element can be effectively improved.

Referring to fig. 2 to fig. 4, based on the above method for manufacturing the absorption core of the heat dissipation device, the embodiment of the invention further provides a heat dissipation device 100.

Specifically, the heat dissipation element 100 includes a metal housing 2, an absorption core 1, and a heat dissipation working medium. The metal shell 2 has an accommodating cavity 10, and the metal shell 2 includes a first shell 21 and a second shell 22, the first shell 21 includes a bottom wall 211, a side wall 212 and convex columns 213, the side wall 212 extends from the edge of the bottom wall 211 toward the second shell 22 and abuts against the second shell 22, the convex columns 213 extend from the bottom wall 211 toward the second shell 22, and meanwhile, the convex columns 213 are arranged at intervals, such as being distributed in an array at intervals, and the accommodating cavity 10 is formed by the first shell 21 and the second shell 22; the absorbent core 1 is the absorbent core 1 obtained by the preparation method, and the absorbent core 1 is accommodated in the accommodating cavity 10 and abuts against the end part of the convex column 213; the heat dissipation working medium can be deionized water, ethanol, acetone and the like, and is filled in the accommodating cavity 10.

In order to better illustrate the technical solution of the present invention, the following is further explained by several embodiments.

Example 1

Referring to fig. 1 to 4, the present embodiment provides a method for manufacturing an absorbent core 1 of a heat dissipation device 100 and the heat dissipation device 100. The preparation method of the absorption core 1 of the heat dissipation element 100 comprises the following steps:

(1) preparing a mixed solution of 0.5mol/L sodium hydroxide and 0.3mol/L sodium carbonate;

(2) and (2) soaking the clean and dry copper wire absorption core body in the mixed solution obtained in the step (1) at the temperature of 50 ℃ for 0.5h, washing with deionized water, taking out, and drying at room temperature to obtain the absorption core 1.

The heat dissipation element 100 comprises the absorption core 1 obtained by the preparation method.

Example 2

Referring to fig. 1 to 4, the present embodiment provides a method for manufacturing an absorption core 1 of a heat dissipation device 100 and the heat dissipation device 100. The preparation method of the absorption core 1 of the heat dissipation element 100 comprises the following steps:

(1) preparing a mixed solution of 0.3mol/L sodium hydroxide and 0.1mol/L sodium carbonate;

(2) and (2) soaking the clean and dry copper wire absorption core body in the mixed solution obtained in the step (1) at the temperature of 80 ℃ for 1.0h, washing with deionized water, taking out, and drying at room temperature to obtain the absorption core 1.

EXAMPLE 3

Referring to fig. 1 to fig. 4, the present embodiment provides a method for preparing an absorption core 1 of a heat dissipation device 100 and the heat dissipation device 100, wherein the method for preparing the absorption core 1 of the heat dissipation device 100 includes the following steps:

(1) preparing a mixed solution of 0.6mol/L sodium hydroxide and 0.4mol/L sodium carbonate;

(2) and (2) soaking the clean and dry copper mesh absorption core body in the mixed solution obtained in the step (1) at the temperature of 40 ℃ for 2.0h, washing with deionized water, taking out, and drying at room temperature to obtain the absorption core 1.

Example 4

(2) and (2) soaking the clean and dry copper mesh absorption core body in the mixed solution obtained in the step (1) at the temperature of 40 ℃ for 2.0h, then transferring to room temperature, soaking in sulfuric acid with the mass concentration of 10% for 1min, then washing with deionized water, taking out and drying at room temperature to obtain the absorption core 1.

Example 5

(1) preparing a mixed solution of 0.5mol/L sodium hydroxide and 0.2mol/L sodium carbonate;

(2) and (2) soaking the clean and dry foamy copper absorption core body in the mixed solution obtained in the step (1) at the temperature of 60 ℃ for 1.0h, washing with deionized water, taking out, and drying at room temperature to obtain the absorption core 1.

Example 6

(2) and (2) soaking the clean and dry foamy copper absorption core body in the mixed solution obtained in the step (1) at the temperature of 60 ℃ for 2.0h, washing with deionized water, taking out, and drying at room temperature to obtain the absorption core 1.

Example 7

(1) preparing a mixed solution of 3.0mol/L sodium hydroxide and 1.0mol/L sodium carbonate;

(2) and (2) placing the clean and dry copper-etched continuous linear type absorption core body into the mixed solution obtained in the step (1) at the temperature of 60 ℃ for soaking for 4.0h, washing by using deionized water, taking out and drying at room temperature to obtain the absorption core 1.

Example 8

(2) and (2) placing the clean and dry copper-etched discontinuous staggered absorption core body in the mixed solution obtained in the step (1) at the temperature of 60 ℃ for soaking for 4.0h, washing with deionized water, taking out and drying at room temperature to obtain the absorption core 1.

In order to better verify the heat dissipation effect of the absorbent core 1 prepared by the embodiment of the present invention and the heat dissipation element 100 assembled by the absorbent core, the following comparative examples are also provided in the present invention:

comparative example 1

An absorbent core 1, wherein the absorbent core 1 is the copper wire absorbent core body in example 1;

the heat dissipating member 100 includes the copper wire absorbent core body in embodiment 1.

Comparative example 2

An absorption core 1, wherein the absorption core 1 is the copper mesh absorption core body in the embodiment 3;

the heat dissipating member 100 includes the copper mesh absorbent core body of embodiment 3.

Comparative example 3

An absorbent core 1, wherein the absorbent core 1 is the foam copper absorbent core body in the example 5;

a heat-dissipating component 100 comprising the copper foam absorbent core body of example 5.

Comparative example 4

An absorbent core 1, the absorbent core 1 being the copper etched continuous rectilinear absorbent core body of example 7;

the heat-dissipating component 100, comprising the copper etched continuous rectilinear absorbent core body of example 7.

Performance test

The heat dissipation performance of the absorbent cores 1 and the corresponding heat dissipation elements 100 in examples 1 to 8 and comparative examples 1 to 4 was verified by the following method:

(I) hydrophilicity

Equipment: measuring by a contact angle tester;

test medium: deionized water;

the test method comprises the following steps: the absorbent cores 1 of examples 1-8 and comparative examples 1-4 were tested at room temperature and the contact angles were measured at 3 different positions for each sample, averaged and reported in table 1 as the contact angle of the sample.

(II) capillary force

The test method comprises the following steps: the absorbent cores 1 of examples 1 to 8 and comparative examples 1 to 4 were used as samples, and the samples were immersed in deionized water for 1min, respectively, while the size of each sample immersed in deionized water was 5 mm.

The time required for the working medium of deionized water to soak the entire sample was recorded, each sample was tested 3 times, the average value was recorded in table 1, and the capillary force of the absorbent core 1 was evaluated therefrom.

(III) water absorption weight

The weight of the absorbent core 1 before and after the absorption of water was recorded for each sample, the difference in weight was recorded as the weight of water absorbed by the corresponding absorbent core 1, the test was repeated 3 times for each sample, the average value was recorded in table 1, and the absorbent weight of the absorbent core 1 was evaluated therefrom.

(V) efficiency of heat-dissipating element

The test method comprises the following steps: the heat dissipating elements 100 of examples 1 to 8 and comparative examples 1 to 4 were subjected to a heat transfer test, and 5 sets of temperature differences between the evaporation end 200 and the condensation end 300 at the same position were recorded in each heat dissipating element 100, and the average value was recorded in table 1, and the heat transfer performance of the heat dissipating element 100 was evaluated based thereon.

TABLE 1 comparison of Performance between examples 1-8 and comparative examples 1-4

Examples of the invention	Contact angle (°)	Capillary force(s)	Absorbent weight (g)	Heat transfer Property (. degree. C.)
					Example 1	0	8	0.02	1.9
Example 2	0	9	0.02	2.0
					Example 3	0	40	0.11	2.5
Example 4	0	45	0.11	3.0
					Example 5	0	60	0.09	5.9
Example 6	0	40	0.18	2.4
					Example 7	0	20	0.07	2.1
Example 8	0	50	0.02	5.8
					Comparative example 1	80	24	0.01	5.4
Comparative example 2	108	-	0	14.5
					Comparative example 3	102	-	0	13.6
Comparative example 4	110	-	0	16.5

Note "-" indicates no capillary force

Observing table 1, the following conclusions are reached:

it can be seen from the combination of examples 1 to 8 and comparative examples 1 to 4 that the contact angle and capillary force of the absorbent core 1 obtained after the alkaline solution immersion etching treatment of the absorbent core body made of metal materials such as copper wire, copper mesh, copper foam or copper etching capillary structure are greatly improved, so that the heat pipe or the vapor chamber made of the absorbent core body made of metal materials has more excellent heat transfer performance, because the alkaline solution can microetch the absorbent core body made of metal materials, especially the absorbent core body made of copper, and a nano-scale concave-convex structure is formed on the surface of the absorbent core body made of metal materials, and the surface of the concave-convex structure can generate basic copper carbonate with hydrophilic performance. However, the sizes of the capillary structures of the obtained absorbent cores 1 are different due to the differences of the absorbent core body structures and the soaking conditions, so the absorbent weights of the absorbent cores 1 prepared by different absorbent core bodies are greatly different.

Combining example 3 and example 4, it can be seen that the soaking plate made of the copper mesh absorbent core body has excellent heat transfer performance even if the basic copper carbonate on the surface is cleaned after the copper mesh absorbent core body is soaked in the alkaline solution.

Combining examples 3 and 4 and comparative example 2, it can be seen that the main influence factor of the performance of the copper mesh absorbent core 1 is the nano-scale concave-convex structure on the copper mesh fibers, and the basic copper carbonate on the surface of the copper mesh absorbent core 1 has a promoting effect on the performance.

Combining examples 7 and 8, it can be seen that, because the microetching ability of the alkaline solution to the copper absorbent core body is limited, the copper etching of the absorbent core body requires a long treatment time (4 hours) to significantly increase the capillary force of the absorbent core 1; the reason why the alkaline solution has the best microetching effect on the continuous linear etching pattern and has the worse microetching effect on the discontinuous dislocation type etching pattern is that a continuous nano concave-convex structure can be constructed on the absorption core body of the continuous linear etching pattern, which is beneficial to the improvement of capillary action force, so that the temperature difference between the two ends of the evaporation end and the condensation end of the radiating element 100 can be reduced, the heat transfer performance of the radiating element 100 is improved, and the alkaline solution treatment cannot construct a continuous nano concave-convex structure on the discontinuous dislocation type etching pattern, so that the microetching effect is limited.

Combining examples 1 and 2, it can be seen that when the concentrations of sodium hydroxide and sodium carbonate in the alkaline solution are too low, such as sodium hydroxide below 0.3mol/L and sodium carbonate below 0.1mol/L, the microetching capability of the copper absorbent core is weak, and the surface of the copper absorbent core needs to be obviously changed by raising the temperature and prolonging the time; the highest amounts of sodium hydroxide and sodium carbonate added to the alkaline solution are limited by the solubility of sodium hydroxide and sodium carbonate.

It should be noted that the combination of potassium hydroxide, potassium carbonate and other common strong bases and carbonates which are easily dissolved in water can also be used as the alkaline solution for preparing the absorbent core 1, and the effect of the combination is not much different from that of the mixed solution of sodium hydroxide and sodium carbonate, and thus the description thereof is omitted here.

In combination with the above, it can be seen that the alkaline solution can perform effective surface microetching of the absorbent core body to obtain an absorbent core 1 having a higher capillary force and hydrophilic properties.

While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

Claims

1. A method of making an absorbent core for a heat-dissipating component, comprising the steps of:

providing a copper absorbent core body;

soaking the absorbent core body in an alkaline solution;

wherein the alkaline solution contains 0.3-3.0 mol/L alkali and 0.1-1.0 mol/L carbonate; the soaking temperature is 40-80 ℃, and the soaking time is 0.5-4.0 h;

the alkali is selected from at least one of sodium hydroxide and potassium hydroxide, and the carbonate is selected from at least one of sodium carbonate and potassium carbonate.

2. The method of claim 1, wherein the alkali solution comprises 0.5-3.0 mol/L alkali and 0.3-1.0 mol/L carbonate.

3. The method of claim 1, wherein the soaking temperature is 40 ℃ to 60 ℃ and the soaking time is 1.0h to 4.0 h.

4. The method for producing an absorbent core for a heat-radiating member according to claim 1 or 2, wherein the absorbent core body is selected from any one of a copper mesh, a copper wire, a copper powder sintered body, a copper foam, and a copper etched capillary structure.

5. The method of claim 4, wherein the surface of the absorbent core is adhered with basic copper carbonate.

6. A radiating element comprises a metal shell with a containing cavity, an absorption core contained in the containing cavity and a radiating working medium filled in the containing cavity, and is characterized in that the absorption core is prepared by the preparation method of the absorption core of the radiating element according to any one of claims 1 to 5.

7. The heat-dissipating element according to claim 6, wherein the surface of the absorbent core has a nano-scale relief structure.

8. The heat dissipating element of claim 7, wherein the absorbent core is a copper absorbent core and the relief structure has basic copper carbonate attached to a surface thereof.