CN114959398A - Metal structural member used in cooperation with gallium-based liquid metal and manufacturing method and application thereof - Google Patents

Abstract

The invention discloses a metal structural member used for being matched with gallium-based liquid metal, which is provided with a high-phosphorus nickel alloy layer on the surface of the metal structural member, which is in contact with the gallium-based liquid metal. When the metal structural member is in contact with the gallium-based liquid metal, the metal structural member cannot react with the gallium-based liquid metal, so that the heat dissipation performance reduction caused by the consumption of the gallium-based liquid metal is avoided. The invention also discloses a preparation method of the metal structural part and application of the metal structural part in heat dissipation of computer chips, mobile phone chips, communication products, high-power LEDs, insulated gate bipolar transistors and high-power electronic products.

Description

Metal structural member used in cooperation with gallium-based liquid metal and manufacturing method and application thereof

Technical Field

The invention belongs to the field of heat conduction of electronic equipment, and particularly relates to a metal structural member used for being matched with gallium-based liquid metal, and a preparation method and application thereof.

Background

There are fine asperity gaps between the electronic material surface and the heat sink, and if they are mounted directly together, the actual contact area between them is only 10% of the area of the heat sink base, and the remainder is an air gap. Because the thermal conductivity of air is only 0.024W/(m.K), the contact thermal resistance between the electronic component and the heat sink is very large, the heat conduction is seriously hindered, and the efficiency of the heat sink is low. Therefore, a thermal interface material with high thermal conductivity is required to fill the gaps, remove air therein, and establish a thermal conduction channel between the electronic component and the heat sink, so as to greatly increase the contact area between the heat source and the heat sink, reduce the thermal contact resistance, and make the heat sink function well.

Thermal silicone grease is currently used as a traditional thermal interface material. But with the rise of fields such as emerging 5G communication, thing networking, new energy automobile electron, wearable equipment, wisdom city, relevant electronic device is towards miniaturization, high power density, multi-functionalization etc. direction development, and this will make relevant electronic device's overheat risk continuously promote, and traditional silicone grease heat conductivity is low, can not satisfy the user demand. The development of high performance thermal interface materials is critical to improve heat dissipation of electronic devices and is also the biggest challenge in academic and electronic device application industries. Gallium-based liquid metal thermal interface materials have gained increasing attention in recent years due to their high thermal conductivity, which can satisfy modern high power density applications.

However, since the gallium-based liquid metal can react with aluminum or its alloy, an intermetallic compound is formed on copper or its alloy, while most of the heat spreader materials are copper, aluminum or its alloy, which causes the liquid-phase gallium to react and consume, and finally the interface becomes dry, resulting in failure without filling effect. Therefore, avoiding the reaction between the gallium-based liquid metal and the copper, the aluminum or the alloy thereof is a problem to be solved in need of wide application of the liquid metal as a thermal interface material.

The information disclosed in this background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

Disclosure of Invention

The invention aims to provide a metal structural member used for being matched with gallium-based liquid metal, which can not react with the gallium-based liquid metal when contacting with the gallium-based liquid metal, thereby avoiding the reduction of heat dissipation performance caused by the consumption of the gallium-based liquid metal and solving the technical problem that the interface is dried and loses the filling effect because the liquid-phase gallium is consumed by the reaction of the gallium-based liquid metal and aluminum or an alloy thereof in a radiator material in the prior art.

To achieve the above objects, the present invention provides a metal structure for use with a gallium-based liquid metal having a high-phosphorous nickel alloy layer on a surface of the metal structure in contact with the gallium-based liquid metal.

In one embodiment of the present invention, the phosphorus content in the high phosphorus-nickel alloy layer is greater than or equal to 10%.

In one embodiment of the invention, the thickness of the high-phosphorus nickel alloy layer is more than or equal to 1 μm; preferably, the thickness of the high-phosphorus nickel alloy layer is more than or equal to 3 mu m; more preferably, the thickness of the high-phosphorus nickel alloy layer is more than or equal to 5 μm; most preferably, the thickness of the high-phosphorus nickel alloy layer is more than or equal to 10 μm.

In an embodiment of the present invention, the metal structural member is a heat dissipation assembly contacting with the gallium-based liquid metal, a container or a cavity containing the gallium-based liquid metal, or a gallium-based liquid metal flow pipe; preferably, the metal structural part is a fin radiator, a heat pipe radiator, a phase change radiator, a heat sink, a vapor chamber, a micro-channel radiator, a liquid metal fluid radiator, a liquid metal pressure sensor, a liquid metal pressure transmitter, a liquid metal container or a part thereof contacting with the gallium-based liquid metal.

In one embodiment of the present invention, a surface of the metal structural member, which is in contact with the gallium-based liquid metal, is a flat surface or a curved surface.

In an embodiment of the present invention, the material of the metal structural member is selected from at least one of copper, aluminum, iron, nickel, stainless steel, titanium, zinc, gold, or an alloy thereof.

In one embodiment of the present invention, the metal structure further includes a protective layer of composite ceramic on a surface of the metal structure in contact with the gallium-based liquid metal.

In one embodiment of the present invention, the gallium-based liquid metal is selected from the group consisting of gallium metal, gallium-containing liquid alloys, gallium-containing metal oxides, gallium-containing thermal interface materials, and gallium-containing composite materials.

Another object of the present invention is to provide the above method for manufacturing a metal structural member, wherein a high-phosphorus nickel alloy layer is formed on the surface of the metal structural member in contact with the gallium-based liquid metal thermal interface material by performing a high-phosphorus electroless nickel plating treatment on the surface of the metal structural member in contact with the gallium-based liquid metal thermal interface material. The method has the advantages of mature and stable technology and low cost.

The invention also aims to provide application of the metal structural part or the metal structural part prepared by the preparation method in heat dissipation of computer chips, mobile phone chips, communication products, high-power LEDs, insulated gate bipolar transistors and high-power electronic products. The invention prevents the alloying reaction between the gallium-based liquid metal and the metal structural member by forming the high-phosphorus nickel alloy layer on the surface of the metal structural member, which is in contact with the gallium-based liquid metal, so that the high-heat-conductivity gallium-based liquid metal can be widely applied to products such as computer chips, mobile phone chips, communication products, high-power LEDs, insulated gate bipolar transistors, aviation or military high-power electronic products and the like.

Compared with the prior art, the invention has the following beneficial effects:

(1) the high-phosphorus nickel alloy layer on the surface of the metal structural member can effectively protect metals such as copper, aluminum and the like, and does not react with gallium-based liquid metal for a long time under extreme conditions. According to the experimental result, the high-phosphorus nickel coating with the thickness of more than 1 mu m can prevent the metal sheet from reacting with the gallium-based liquid metal, so that the gallium-based liquid metal is prevented from being gradually consumed through reaction, and the heat conductivity is prevented from being reduced due to the consumption of the gallium-based liquid metal thermal interface material.

(2) Although the high phosphorus nickel plating layer of 1 μm or more has a good protective effect on the metal structural member, the thickness of the high phosphorus nickel plating layer is preferably 3 μm or more, more preferably 5 μm or more, in view of the possibility of abrasion or scratching of the high phosphorus nickel plating layer during packaging, transportation, and use, in the case of the metal structural member in which the high phosphorus nickel plating layer of the heat sink, the temperature equalization plate, and the like is exposed on the surface. Under the conditions of severe abrasion or special requirements on high stability, long service cycle and the like, a high-phosphorus nickel coating with the thickness of more than 10 microns can be formed on the surface of the metal structural member so as to fully ensure the sufficient protection effect and avoid the occurrence of accidents.

(3) In addition, the phosphorus content in the high-phosphorus nickel alloy layer is also important, and the comparative example 2 adopts a medium-phosphorus nickel plating layer with the phosphorus content of 9% for protection, but experimental results show that although the medium-phosphorus nickel plating layer plays a certain role in protecting the metal sheet from reacting with the gallium-based liquid metal, the protection effect is not sufficient, and the gallium-based liquid metal finally reacts with the metal sheet.

Drawings

FIG. 1 is a schematic cross-sectional view of a fin heat sink according to an embodiment of the present invention;

FIG. 2 is a schematic cross-sectional view of a heat pipe heat sink according to an embodiment of the present invention;

FIG. 3 is a schematic cross-sectional view of a liquid metal containment vessel according to one embodiment of the invention;

FIG. 4 is a photograph showing the plating protective effect of the metal sheets treated according to the methods of example 3 and comparative examples 1 to 5 of the present invention.

Description of the main reference numerals:

1-metal structural member, 2-high phosphorus nickel alloy layer and 3-gallium-based liquid metal.

Detailed Description

The following detailed description of the embodiments of the present invention is provided in conjunction with the accompanying drawings, and it should be understood that the scope of the invention is not limited to the specific embodiments.

Throughout the specification and claims, unless explicitly stated otherwise, the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element or component but not the exclusion of any other element or component.

Example 1

As shown in fig. 1, a metal structure 1, in particular a copper finned heat sink, has a high phosphorus-nickel alloy layer 2 on the bottom surface in contact with a gallium-based liquid metal 3. The preparation method comprises the following steps: and cleaning the bottom surface of the copper fin radiator, which is in contact with the gallium-based liquid metal, performing high-phosphorus chemical nickel plating for 5 minutes, taking out and drying.

The thickness of the high-phosphorus nickel alloy layer formed on the bottom surface of the copper finned heat sink is 1.2 mu m, and the phosphorus content in the high-phosphorus nickel alloy layer is 10%. For the convenience of subsequent experiments, a 2mm copper sheet is synchronously used for high-phosphorus chemical nickel plating treatment, and then the treated copper sheet is used for replacing a copper fin radiator to be used as a test object in the embodiment 1.

Example 2

As shown in fig. 2, a metal structural member 1, specifically a heat pipe of a copper heat pipe radiator, has a high-phosphorus nickel alloy layer 2 on the inner surface in contact with a gallium-based liquid metal 3. The preparation method comprises the following steps: the inner surface of the heat pipe of the copper heat pipe radiator, which is contacted with the gallium-based liquid metal, is cleaned, high-phosphorus chemical nickel plating treatment is carried out for 18 minutes, and the heat pipe is taken out and dried.

The thickness of the high-phosphorus nickel alloy layer formed on the surface of the copper temperature-uniforming plate is 3 mu m, and the phosphorus content in the high-phosphorus nickel alloy layer is 12%. For the convenience of subsequent experiments, a 2mm copper sheet is synchronously used for high-phosphorus chemical nickel plating treatment, and then the treated copper sheet is used for replacing a copper heat pipe to be used as a test object in the embodiment 2.

Example 3

As shown in fig. 3, a metal structure 1, in particular a copper liquid metal containment vessel, has a high phosphorus nickel alloy layer 2 on the inner surface in contact with a gallium-based liquid metal 3. The preparation method comprises the following steps: cleaning the inner surface of the copper liquid metal container, which is in contact with the gallium-based liquid metal, performing high-phosphorus chemical nickel plating for 24 minutes, taking out and drying.

The thickness of the high-phosphorus nickel alloy layer formed on the inner surface of the copper liquid metal container is 5 microns, and the phosphorus content in the high-phosphorus nickel alloy layer is 11%. For the convenience of subsequent experiments, 2mm copper sheets were synchronously used for high-phosphorus chemical nickel plating, and then the treated copper sheets were used as the test objects in example 3 instead of copper liquid metal containers.

Example 4

A micro flow channel heat sink made of copper has a high-phosphorus nickel alloy layer on the inner and outer surfaces in contact with a gallium-based liquid metal. And cleaning the inner surface and the outer surface of the copper micro-channel radiator in contact with the gallium-based liquid metal, carrying out high-phosphorus chemical nickel plating treatment for 40 minutes, taking out and drying.

The thickness of the high-phosphorus nickel alloy layer formed on the inner surface and the outer surface of the copper micro-flow channel radiator is 10 mu m through measurement, and the phosphorus content in the high-phosphorus nickel alloy layer is 10 percent. For the convenience of subsequent experiments, 2mm copper sheets were synchronously used for high-phosphorus electroless nickel plating, and then the treated copper sheets were used as test objects in example 4 instead of copper micro-channel radiators.

Example 5

An aluminum heat sink having a high phosphorus-nickel alloy layer on a bottom surface in contact with a gallium-based liquid metal. And cleaning the bottom surface of the aluminum heat sink in contact with the gallium-based liquid metal, carrying out high-phosphorus chemical nickel plating for 20 minutes, taking out and drying.

The thickness of the high phosphorus-nickel alloy layer formed on the surface of the aluminum heat sink is 5 μm, and the phosphorus content in the high phosphorus-nickel alloy layer is 10%. For the convenience of subsequent experiments, 2mm aluminum sheets were used simultaneously for high-phosphorous electroless nickel plating, and then the treated aluminum sheets were used as test objects in example 5 instead of aluminum heat sinks.

Example 6

A copper alloy heat sink having a high phosphorous nickel alloy layer on a bottom surface in contact with the gallium-based liquid metal. And cleaning the bottom surface of the copper alloy heat sink in contact with the gallium-based liquid metal, carrying out high-phosphorus chemical nickel plating for 20 minutes, taking out and drying.

The thickness of the high-phosphorus nickel alloy layer formed on the surface of the copper alloy heat sink is 5 μm, and the phosphorus content in the high-phosphorus nickel alloy layer is 10%. For the convenience of subsequent experiments, 2mm copper alloy sheets were used to replace copper alloy heat sinks for high phosphorus electroless nickel plating as the test object of example 6.

Example 7

An aluminum alloy heat sink having a high phosphorus-nickel alloy layer on a bottom surface in contact with a gallium-based liquid metal. And cleaning the bottom surface of the aluminum alloy heat sink in contact with the gallium-based liquid metal, carrying out high-phosphorus chemical nickel plating for 29 minutes, taking out and drying.

The thickness of the high-phosphorus nickel alloy layer formed on the surface of the aluminum alloy heat sink is 5 mu m, and the phosphorus content in the high-phosphorus nickel alloy layer is 10%. For the convenience of subsequent experiments, 2mm aluminum alloy sheets were used to replace aluminum alloy heat sinks for high phosphorus electroless nickel plating as the test object of example 7.

Example 8

A stainless steel heat sink having a high phosphorus nickel alloy layer on a bottom surface in contact with the gallium based liquid metal. And cleaning the bottom surface of the stainless steel heat sink in contact with the gallium-based liquid metal, carrying out high-phosphorus chemical nickel plating treatment for 29 minutes, taking out and drying.

The thickness of the high-phosphorus nickel alloy layer formed on the surface of the stainless steel heat sink is 5 μm, and the phosphorus content in the high-phosphorus nickel alloy layer is 10%. For the convenience of subsequent experiments, 2mm stainless steel sheets were used to replace stainless steel heat sinks for high phosphorus electroless nickel plating as the test object of example 8.

Comparative example 1

The surface of a 2mm copper sheet was cleaned and was not treated.

Comparative example 2

And cleaning the surface of a 2mm copper sheet, carrying out medium-phosphorus chemical nickel plating treatment for 18 minutes, taking out and drying. The thickness of the medium phosphorus nickel alloy layer formed on the surface of the copper sheet was measured to be 5 μm, and the phosphorus content in the medium phosphorus nickel alloy layer was 9%.

Comparative example 3

And cleaning the surface of a 2mm copper sheet, and performing chromium electroplating treatment. The thickness of the chromium electroplating layer formed on the surface of the copper sheet was measured to be 5 μm.

Comparative example 4

And cleaning the surface of a 2mm copper sheet, and performing nickel electroplating treatment. The thickness of the electroplated nickel layer formed on the surface of the copper sheet was measured to be 5 μm.

Comparative example 5

And cleaning the surface of a 2mm copper sheet, and coating 207E high-thermal-conductivity ceramic paint. The thickness of the high thermal conductive ceramic layer formed on the surface of the copper sheet was measured to be 5 μm.

Test of protective effect of plating layer in Experimental example

The metal sheets treated in the methods of examples 1 to 8 and comparative examples 1 to 4 were used as the objects to be tested. Two metal sheets to be tested are used as a group, gallium-based liquid metal is coated in the middle of one metal sheet, sealant is coated around the liquid metal to prevent the liquid metal from leaking, the other metal sheet is buckled with the metal sheet coated with the liquid metal, and the two metal sheets keep a distance of about 1mm and are fixed by a clamp. And (3) placing each group of fixed metal sheets into a programmable constant temperature and humidity test box, and stabilizing the temperature of the constant temperature and humidity test box at minus 40 ℃ and 80 ℃ for 30min respectively, so as to perform high and low temperature cycle test by taking the temperature as one cycle, wherein the cycle test frequency is 1000 times. After the test is finished, separating each group of metal sheets, removing the liquid metal, and checking the reaction condition of the metal sheets and the liquid metal. The test results are shown in table 1 below:

TABLE 1 test results

The test result shows that: none of the metal sheet surfaces with the high phosphorus nickel alloy layers treated according to examples 1-8 had any reaction marks, the coating surfaces were clearly washable, the surfaces of comparative examples 2 and 5 had little reaction marks, and the surfaces of comparative examples 1, 3 and 4 had a larger area of reaction marks.

The test results show that the high-phosphorus nickel coating with the thickness of more than 1 mu m can prevent the metal sheet from reacting with the gallium-based liquid metal, so that the gallium-based liquid metal is prevented from being gradually consumed through reaction, and the heat conductivity is prevented from being reduced due to the consumption of the gallium-based liquid metal thermal interface material. Although the high phosphorus nickel plating layer of 1 μm or more has a good protective effect on the metal structural member, the thickness of the high phosphorus nickel plating layer is preferably 3 μm or more, more preferably 5 μm or more, in view of the possibility of abrasion or scratching of the high phosphorus nickel plating layer during packaging, transportation, and use, in the case of the metal structural member in which the high phosphorus nickel plating layer of the heat sink, the temperature equalization plate, and the like is exposed on the surface. Under the conditions of severe abrasion or special requirements on high stability, long service cycle and the like, a high-phosphorus nickel coating with the thickness of more than 10 microns can be formed on the surface of the metal structural member so as to fully ensure the sufficient protection effect and avoid the occurrence of accidents.

The surface of the untreated copper sheet of comparative example 1 was not cleaned and the imprint area reached about 35%, indicating that the metal sheet reacted with the gallium-based liquid metal in a large amount, which resulted in a decrease in thermal conductivity due to consumption of the gallium-based liquid metal thermal interface material. Comparative example 2 the metal sheet cladding surface of cladding medium phosphorus nickel cladding has a little seal of a government organization in old china, seal of a government organization in old china area is about 5% with gallium base liquid metal contact area, obviously less than comparative example 1, prove that the medium phosphorus nickel cladding that the phosphorus content is 9% has played certain guard action to preventing the metal sheet from reacting with gallium base liquid metal, but the guard action is not sufficient yet, gallium base liquid metal has still reacted with the metal sheet finally. The comparative examples 3-5 have similar effects with the comparative example 2, the comparative example 3 covers the electroplated chromium layer, the comparative example 4 covers the electroplated nickel layer and the comparative example 5 covers the metal sheet coating surface of the ceramic layer, the marking areas are respectively 15%, 25% and 3%, and are obviously less than the comparative example 1, which shows that the electroplated chromium layer, the electroplated nickel layer and the ceramic layer play a certain protection role in preventing the metal sheet from reacting with the gallium-based liquid metal, but the protection strength is obviously weaker than that of the high-phosphorus nickel coating.

The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. It is not intended to limit the invention to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teaching. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and its practical application to enable one skilled in the art to make and use various exemplary embodiments of the invention and various alternatives and modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims and their equivalents.

Claims (10)

1. A metal structure for use with a gallium-based liquid metal, characterized by a high-phosphorous nickel alloy layer on a surface of the metal structure in contact with the gallium-based liquid metal.

2. The metallic structure of claim 1, wherein the high phosphorus nickel alloy layer has a phosphorus content of 10% or more.

3. The metallic structure according to claim 1, wherein the thickness of the high-phosphorus nickel alloy layer is greater than or equal to 1 μm; preferably, the thickness of the high-phosphorus nickel alloy layer is more than or equal to 3 mu m; more preferably, the thickness of the high-phosphorus nickel alloy layer is more than or equal to 5 μm; most preferably, the thickness of the high-phosphorus nickel alloy layer is more than or equal to 10 μm.

4. The metallic structure of claim 1, wherein the metallic structure is a component in contact with a gallium-based liquid metal, a container or chamber containing a gallium-based liquid metal, or a gallium-based liquid metal flow conduit; preferably, the metal structural part is a fin radiator, a heat pipe radiator, a phase change radiator, a heat sink, a vapor chamber, a micro-channel radiator, a liquid metal fluid radiator, a liquid metal pressure sensor, a liquid metal pressure transmitter, a liquid metal container or a part thereof contacting with the gallium-based liquid metal.

5. The metallic structure of claim 1, wherein a surface of the metallic structure in contact with the gallium-based liquid metal is planar or curved.

6. The metallic structure of claim 1, wherein the metallic structure is made of a material selected from at least one of copper, aluminum, iron, nickel, stainless steel, titanium, zinc, gold, or alloys thereof.

7. The metallic structure of claim 1, further comprising a nanocomposite ceramic coating on a surface of the metallic structure in contact with the gallium-based liquid metal.

8. The metallic structure of claim 1, wherein the gallium-based liquid metal is selected from any one or more of gallium metal, gallium-containing liquid alloys, gallium-containing metal oxides, gallium-containing thermal interface materials, gallium-containing composite materials.

9. A method of making a metallic structural member as claimed in any one of claims 1 to 8, comprising the steps of: and performing high-phosphorus chemical nickel plating treatment on the surface of the metal structural part in contact with the gallium-based liquid metal thermal interface material, so as to form a high-phosphorus nickel alloy layer on the surface of the metal structural part in contact with the gallium-based liquid metal.

10. Use of the metal structure according to any one of claims 1 to 8 or the metal structure produced by the method according to claim 9 for heat dissipation in computer chips, mobile phone chips, communication products, high-power LEDs, insulated gate bipolar transistors, and high-power electronic products.

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