Heat dissipation devices, their fabrication methods, and electronic devices

Abstract

This application provides a heat dissipation device, its fabrication method, and an electronic device. The heat dissipation device includes a stacked metal heat dissipation layer, a connecting layer, and a carbonaceous thermally conductive layer. The connecting layer is made of titanium and other metallic materials contained in the metal heat dissipation layer. The heat dissipation device further includes an alloy layer and a titanium carbide layer. The alloy layer is located between the metal heat dissipation layer and the connecting layer, and is used to connect the metal heat dissipation layer and the connecting layer. The titanium carbide layer is located between the carbonaceous thermally conductive layer and the connecting layer, and is used to connect the carbonaceous thermally conductive layer and the connecting layer. This application utilizes a connecting layer with mixed materials to connect the carbonaceous thermally conductive layer and the metal heat dissipation layer, enabling the use of the carbonaceous thermally conductive layer in the field of thermal pads.

Description

Technical Field

[0001] This application relates to the field of heat dissipation technology, and in particular to a heat dissipation device, its preparation method, and an electronic device. Background Technology

[0002] A thermal pad is a gap-filling material with excellent thermal conductivity, often used for heat transfer between smaller heat-generating products (such as chips) and heat sinks. To eliminate air between the heat-generating product and the heat sink, and to accommodate the dimensional tolerances of the heat-generating product, a thermal pad should generally have good flexibility, compressibility, and thermal conductivity to ensure sufficient contact between the heat-generating product and the heat sink, facilitating timely heat dissipation.

[0003] To meet the required flexibility, compressibility, and thermal conductivity, traditional thermal pads are mostly made of polymer materials filled with thermally conductive particles. These fillers include alumina ceramic particles or boron nitride ceramic particles. However, the thermal conductivity of the particles themselves is not high, and the compatibility between the filler and the polymer matrix is ​​poor, resulting in numerous interfaces and high interfacial thermal resistance, hindering heat conduction. Consequently, the thermal conductivity of traditional thermal pads is mostly between 1 and 5 W / m·K. With the increasing power consumption of heat-generating products and the miniaturization of electronic devices, traditional thermal pads are no longer sufficient to meet the actual heat dissipation requirements of electronic devices.

[0004] Therefore, how to provide a heat dissipation device with good heat dissipation performance has become an urgent technical problem to be solved. Summary of the Invention

[0005] Therefore, it is necessary to provide a heat dissipation device, its preparation method, and an electronic device, which utilizes a connecting layer with a mixed material to connect a carbonaceous thermally conductive layer and a metal heat dissipation layer, thereby effectively improving the heat dissipation effect.

[0006] In a first aspect, this application provides a heat dissipation device, which includes a stacked metal heat dissipation layer, a connecting layer and a carbon thermally conductive layer, wherein the connecting layer is made of titanium and the metal material contained in the metal heat dissipation layer;

[0007] The heat dissipation device further includes an alloy layer and a titanium carbide layer, the alloy layer being located between the metal heat dissipation layer and the connecting layer, and the alloy layer being used to connect the metal heat dissipation layer and the connecting layer;

[0008] The titanium carbide layer is located between the carbonaceous thermally conductive layer and the connecting layer, and the titanium carbide layer is used to connect the carbonaceous thermally conductive layer and the connecting layer.

[0009] In some embodiments, the carbonaceous thermally conductive layer and the titanium carbide layer are integrally formed, and the metallic titanium in the connecting layer diffuses into the carbonaceous thermally conductive layer to form the titanium carbide layer.

[0010] In some embodiments, the metal material in the connecting layer comprises 6% to 10% by mass of the metal heat dissipation layer.

[0011] In some embodiments, the titanium content in the connecting layer is 1% to 3% by mass.

[0012] In some embodiments, the material of the connecting layer also includes a fluxing agent.

[0013] Optionally, the fluxing material in the connecting layer has a mass percentage content of 87% to 93%.

[0014] In some embodiments, the carbonaceous thermally conductive layer is made of at least one of artificial graphite, natural graphite, and graphene. Optionally, the carbonaceous thermally conductive layer is corrugated.

[0015] In some embodiments, the material of the metal heat dissipation layer includes copper or a copper alloy.

[0016] In some embodiments, the thickness of the titanium carbide layer is 1 μm to 3 μm.

[0017] In some embodiments, the thickness of the alloy layer is 3 μm to 5 μm.

[0018] In some embodiments, the thickness of the connecting layer is 10 μm to 20 μm.

[0019] Secondly, this application provides a method for fabricating a heat dissipation device as described in the first aspect, the method comprising:

[0020] A metal heat dissipation layer, a connecting layer, and a carbon thermally conductive layer are sequentially stacked to obtain a laminate. The laminate is then pressurized under heating conditions, forming an alloy layer between the metal heat dissipation layer and the connecting layer, and a titanium carbide layer between the carbon thermally conductive layer and the connecting layer, thus preparing the heat dissipation device.

[0021] In some embodiments, the pressure of the pressurization process is 50 MPa to 100 MPa.

[0022] In some embodiments, the pressurization process takes 10 to 30 minutes.

[0023] In some embodiments, the heating temperature is 850°C to 950°C.

[0024] In some embodiments, both the heating and pressurization processes are performed in a vacuum environment; optionally, the vacuum level of the vacuum environment is ≤0.01 Pa.

[0025] In some embodiments, the thickness of the metal heat dissipation layer is 10 μm to 50 μm.

[0026] In some embodiments, the thickness of the carbonaceous thermally conductive layer is 20 μm to 300 μm.

[0027] In some embodiments, the carbonaceous thermally conductive layer undergoes bending and pleating and horizontal pressing processes sequentially before being laminated.

[0028] Thirdly, this application provides an electronic device that includes a heat dissipation device as described in the first aspect.

[0029] The beneficial effects of this application include:

[0030] This application employs a bonding layer that can bond with the metal heat dissipation layer and the carbon thermal conductive layer. The titanium in the bonding layer can form a titanium carbide layer with the carbon thermal conductive layer, and the metal heat dissipation layer can form an alloy layer with the bonding layer, thereby achieving a stable connection between the metal heat dissipation layer and the carbon thermal conductive layer. Furthermore, the interlayer thermal resistance is low, resulting in excellent heat dissipation performance. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the structure of a heat dissipation device provided in one embodiment of this application.

[0032] Among them, 1-metal heat dissipation layer; 2-connecting layer; 3-carbon thermal conductive layer; 4-alloy layer; 5-titanium carbide layer. Detailed Implementation

[0033] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings. Preferred embodiments of this application are shown in the drawings. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of this application.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0035] Graphite-based materials possess excellent thermal conductivity; for example, graphene has a theoretical thermal conductivity as high as 5300 W / m·K. Therefore, graphite-based materials are ideal thermal pad fillers. However, graphene films or artificial graphite films have low mechanical strength and can be easily torn or damaged due to displacement of the adhered areas, resulting in surface material detachment. Traditional technologies directly use mechanical connections (e.g., bolt connections) to bond graphene films to other heat dissipation structures, leading to poor contact between graphene and the heat dissipation structure, high interfacial thermal resistance, and impaired heat dissipation. This application employs a bonding layer capable of bonding with both the metal heat dissipation layer and the carbonaceous thermal conductive layer, effectively ensuring the stability of the connection between the carbonaceous thermal conductive layer and the metal heat dissipation layer while maintaining high heat dissipation performance.

[0036] The first aspect of this application provides a heat dissipation device, such as... Figure 1 As shown, the heat dissipation device includes a stacked metal heat dissipation layer 1, a connecting layer 2, and a carbon thermally conductive layer 3. The material of the connecting layer 2 includes titanium and the metal materials contained in the metal heat dissipation layer 1.

[0037] The heat dissipation device further includes an alloy layer 4 and a titanium carbide layer 5. The alloy layer 4 is located between the metal heat dissipation layer 1 and the connecting layer 2, and the alloy layer 4 is used to connect the metal heat dissipation layer 1 and the connecting layer 2.

[0038] The titanium carbide layer 5 is located between the carbonaceous thermally conductive layer 3 and the connecting layer 2, and the titanium carbide layer 5 is used to connect the carbonaceous thermally conductive layer 3 and the connecting layer 2.

[0039] In this application, a connecting layer composed of a mixture of metallic materials and titanium is used to connect the carbonaceous thermally conductive layer and the metal heat dissipation layer. A titanium carbide layer is formed between the connecting layer and the carbonaceous thermally conductive layer, thereby ensuring a stable connection between the carbonaceous thermally conductive layer and the connecting layer. Furthermore, the titanium carbide layer has good thermal conductivity, effectively ensuring the thermal conductivity between the carbonaceous thermally conductive layer and the connecting layer. An alloy layer is formed between the connecting layer and the metal heat dissipation layer, which strengthens the connection between the connecting layer and the metal heat dissipation layer, thus realizing the application of the carbonaceous thermally conductive layer in a metal heat dissipation device. In addition, the tight connection between the carbonaceous thermally conductive layer, the connecting layer, and the metal heat dissipation layer in this application reduces the problem of high interfacial thermal resistance caused by air at the connection interface, and solves the problems of high interfacial thermal resistance and poor thermal conductivity in the mechanical connection of the carbonaceous thermally conductive layer.

[0040] It should be noted that, in this application, the carbonaceous thermal conductive layer refers to a layered structure composed of carbon materials that can achieve thermal conductivity.

[0041] In some embodiments, the carbonaceous thermally conductive layer and the titanium carbide layer are integrally formed, with the metallic titanium in the connecting layer penetrating into the carbonaceous thermally conductive layer to form the titanium carbide layer. It should be noted that, in this application, the integral structure of the carbonaceous thermally conductive layer and the titanium carbide layer refers to the diffusion of titanium elements into the surface of the carbonaceous thermally conductive layer, where it reacts directly with the carbon elements on the surface of the carbonaceous thermally conductive layer to form the titanium carbide layer. In other words, one side of the carbonaceous thermally conductive layer exhibits a titanium carbide layer penetrating its surface, thus the carbonaceous thermally conductive layer and the titanium carbide layer are integrally formed.

[0042] In some embodiments, the mass percentage of the metal material in the metal heat dissipation layer of the connecting layer is 6% to 10%, for example, 6.0%, 6.4%, 6.8%, 7.2%, 7.6%, 8.0%, 8.4%, 8.8%, 9.2%, 9.6%, or 10.0%. It should be noted that the mass percentage of the metal material in the metal heat dissipation layer of the connecting layer refers to the proportion of the metal material in the metal heat dissipation layer within the material of the connecting layer.

[0043] This application controls the content of metal material in the connecting layer to ensure the connection stability between the metal heat dissipation layer and the carbon heat conduction layer and the connecting layer. If the content of metal material is too low or too high, it will affect the content of fluxing material, resulting in a higher melting point of the connecting layer. During hot pressing, the connecting layer may not be able to present a molten state. Since the metal heat dissipation layer cannot be melted at the temperature during hot pressing, it will affect the formation of a stable connection structure between the connecting layer and the metal heat dissipation layer and the carbon heat conduction layer respectively.

[0044] In some embodiments, the titanium content in the bonding layer is 1% to 3% by mass, for example, 1.0%, 1.2%, 1.4%, 1.6%, 1.8%, 2.0%, 2.2%, 2.4%, 2.6%, 2.8%, or 3.0%.

[0045] This application controls the titanium content in the connecting layer to ensure good bonding stability between the connecting layer and both the metal heat dissipation layer and the carbon thermal conductive layer. If the titanium content is relatively low, the connecting layer cannot form a good contact bond with either the metal heat dissipation layer or the carbon thermal conductive layer; if the titanium content is relatively high, the flux content will still be too low, affecting the melting point of the connecting layer. Consequently, during hot pressing, while ensuring that the metal heat dissipation layer does not melt, the connecting layer cannot be in a molten state, thus affecting the stable bonding between the connecting layer and both the carbon thermal conductive layer and the metal heat dissipation layer.

[0046] In some embodiments, the material of the connecting layer further includes a fluxing material. Optionally, the mass percentage of the fluxing material in the connecting layer is 87% to 93%, for example, 87.0%, 87.6%, 88.2%, 88.8%, 89.4%, 90.0%, 90.6%, 91.2%, 91.8%, 92.4%, or 93.0%.

[0047] This application controls the content of fluxing material in the connecting layer to ensure good bonding stability between the connecting layer and both the metal heat dissipation layer and the carbon thermal conductive layer. If the fluxing material content is too low, the melting point of the connecting layer will be too high. During hot pressing, the connecting layer cannot be in a molten state at the temperature that prevents the metal heat dissipation layer from melting, affecting the bonding stability between the connecting layer and both the metal heat dissipation layer and the carbon thermal conductive layer. If the fluxing material content is too high, resulting in insufficient content of the metal heat dissipation layer material and titanium, it will also affect the bonding stability between the connecting layer and both the metal heat dissipation layer and the carbon thermal conductive layer.

[0048] It should be noted that the fluxing material in this application refers to a material that can lower the melting point of the alloy material. That is, the connecting layer in this application contains a fluxing material. The function of the fluxing material is to lower the melting point of the connecting layer. By controlling the melting point of the connecting layer material, it is ensured that the properties of the metal heat dissipation layer and the carbon heat conduction layer are not affected during the hot pressing process, and a stable connection is formed between the connecting layer and the metal heat dissipation layer and the carbon heat conduction layer.

[0049] In some embodiments, the carbonaceous thermally conductive layer is made of at least one of artificial graphite, natural graphite, and graphene. Optionally, the carbonaceous thermally conductive layer is corrugated.

[0050] In this application, the carbon heat-conducting layer is configured with a pleated shape. The pleated shape is similar to a serpentine bend on the cross-section of the layered structure, so that the carbon heat-conducting layer as a whole has a bending structure and a vertical structure. The direction of the vertical structure refers to the thickness direction of the carbon heat-conducting layer, so that the carbon heat-conducting layer has good heat conduction effect in both the horizontal and vertical directions.

[0051] In some embodiments, the material of the metal heat dissipation layer includes copper or a copper alloy. Optionally, when the metal heat dissipation layer is made of copper or a copper alloy, the material of the alloy layer includes a titanium-copper alloy.

[0052] Preferably, the fluxing material comprises Ag; more preferably, the material of the connecting layer may be Ag. 27 Cu4Ti. Ag 27 Cu4Ti represents a molar ratio of Ag:Cu:Ti of 27:4:1.

[0053] In this application, Ag is used as a fluxing material. When the metal heat dissipation layer is copper or copper alloy, the connecting layer, except for the titanium carbide layer side and the alloy layer side, forms a copper-silver alloy. That is, the connecting layer between the titanium carbide layer and the alloy layer is mainly a copper-silver alloy. During the hot pressing process, the titanium material diffuses to both sides of the connecting layer, forming a titanium carbide layer and the alloy layer respectively, which has a good thermal conductivity.

[0054] In some embodiments, the thickness of the titanium carbide layer is 1 μm to 3 μm, for example, 1.0 μm, 1.2 μm, 1.4 μm, 1.6 μm, 1.8 μm, 2.0 μm, 2.2 μm, 2.4 μm, 2.6 μm, 2.8 μm or 3.0 μm.

[0055] In some embodiments, the thickness of the alloy layer is 3μm to 5μm, for example, 3.0μm, 3.2μm, 3.4μm, 3.6μm, 3.8μm, 4.0μm, 4.2μm, 4.4μm, 4.6μm, 4.8μm or 5.0μm.

[0056] In some embodiments, the thickness of the connecting layer is 10μm to 20μm, for example, 10μm, 11μm, 12μm, 13μm, 14μm, 15μm, 16μm, 17μm, 18μm, 19μm or 20μm.

[0057] This application controls the thickness of the titanium carbide layer, alloy layer, and connecting layer, which can ensure a stable connection between the metal heat dissipation layer and the carbon thermal conductive layer without affecting the thermal conductivity.

[0058] The second aspect of this application provides a method for fabricating a heat dissipation device as described in the first aspect, the method comprising:

[0059] A metal heat dissipation layer, a connecting layer, and a carbon thermally conductive layer are sequentially stacked to obtain a laminate. The laminate is then pressurized under heating conditions, forming an alloy layer between the metal heat dissipation layer and the connecting layer, and a titanium carbide layer between the carbon thermally conductive layer and the connecting layer, thus preparing the heat dissipation device.

[0060] This application employs a connecting layer with a mixed material directly laminated with a metal heat dissipation layer and a carbonaceous heat-conducting layer. After hot pressing, at the connection between the connecting layer and the metal heat dissipation layer, the metal material diffuses to form an alloy layer between the connecting layer and the metal heat dissipation layer, achieving a stable connection between the connecting layer and the metal heat dissipation layer. Simultaneously, at the connection between the connecting layer and the carbonaceous heat-conducting layer, titanium diffuses into the carbonaceous heat-conducting layer, forming a titanium carbide layer between the carbonaceous heat-conducting layer and the connecting layer, ensuring a stable connection between the carbonaceous heat-conducting layer and the connecting layer. Since the connecting layer, the titanium carbide layer, and the alloy layer all have good thermal conductivity, the heat dissipation device thus has a good heat dissipation effect.

[0061] In some embodiments, the pressure of the pressurization process is 50MPa to 100MPa, for example, 50MPa, 55MPa, 60MPa, 65MPa, 70MPa, 75MPa, 80MPa, 85MPa, 90MPa, 95MPa or 100MPa.

[0062] In this application, the pressure during the hot pressing process is controlled to ensure that the connecting layer can form stable alloy and titanium carbide layers with the metal heat dissipation layer and the carbon thermal conductive layer, respectively. This ensures good contact between the connecting layer and both the metal heat dissipation layer and the carbon thermal conductive layer, resulting in low interfacial thermal resistance. If the pressure is relatively low, the connecting layer may not be able to form sufficient and good contact with the metal heat dissipation layer and the carbon thermal conductive layer, leading to high interfacial thermal resistance. If the pressure is relatively high, the flux material in the connecting layer may overflow, affecting the connection stability.

[0063] In some embodiments, the pressurization treatment time is 10 min to 30 min, for example, 10 min, 12 min, 14 min, 16 min, 18 min, 20 min, 22 min, 24 min, 26 min, 28 min or 30 min.

[0064] In some embodiments, the heating temperature is 850°C to 950°C, for example, 850°C, 860°C, 870°C, 880°C, 890°C, 900°C, 910°C, 920°C, 930°C, 940°C or 950°C.

[0065] In this application, the temperature is controlled during the hot pressing process to ensure that a stable alloy layer and titanium carbide layer are formed between the connecting layer and the metal connecting layer and the carbon thermally conductive layer, respectively, thus ensuring connection stability and low interfacial thermal resistance. If the temperature is relatively low, the connecting layer cannot make sufficient and good contact with the metal heat dissipation layer and the carbon thermally conductive layer, resulting in high interfacial thermal resistance; if the temperature is relatively high, the metal heat dissipation layer may melt, thereby affecting the connection stability.

[0066] In some embodiments, both the heating and pressurization processes are performed in a vacuum environment. Optionally, the vacuum level of the vacuum environment is ≤0.01 Pa, for example, 0.001 Pa, 0.002 Pa, 0.003 Pa, 0.004 Pa, 0.005 Pa, 0.006 Pa, 0.007 Pa, 0.008 Pa, 0.009 Pa, or 0.010 Pa.

[0067] In some embodiments, the thickness of the metal heat dissipation layer is 10μm to 50μm, for example, 10μm, 14μm, 18μm, 22μm, 26μm, 30μm, 34μm, 38μm, 42μm, 46μm or 50μm.

[0068] In some embodiments, the thickness of the carbonaceous thermally conductive layer is 20 μm to 300 μm, for example, 20 μm, 30 μm, 60 μm, 90 μm, 120 μm, 150 μm, 180 μm, 210 μm, 240 μm, 270 μm or 300 μm.

[0069] In some embodiments, the carbonaceous thermally conductive layer undergoes bending and wrinkling treatment and horizontal pressing treatment in sequence before being laminated.

[0070] In this application, the carbon thermal conductive layer is subjected to bending and pleating treatment and horizontal pressing treatment, so that the carbon thermal conductive layer can have a stable pleated shape during the hot pressing process, thereby giving the carbon thermal conductive layer good thermal conductivity in both vertical and horizontal directions.

[0071] In some embodiments, the surfaces of the metal heat dissipation layer and the connecting layer are cleaned.

[0072] Optionally, the cleaning process includes:

[0073] After sanding the surface of the metal heat dissipation layer or connecting layer with sandpaper for 3 to 5 minutes, it is ultrasonically treated in a cleaning agent for 10 to 20 minutes. Alternatively, the cleaning agent can be acetone; the sandpaper can be 2000-3000 grit silicon carbide sandpaper.

[0074] This application improves the bonding effect during hot-pressing composite by cleaning the surfaces of the metal heat dissipation layer and the bonding layer.

[0075] Exemplarily, and without limitation, a method for manufacturing the above-mentioned heat dissipation device is provided, comprising:

[0076] Use 2000-3000 grit silicon carbide sandpaper to polish the surfaces of the metal heat dissipation layer and the connecting layer for 3-5 minutes respectively, and then place them in a cleaning agent for ultrasonic treatment for 10-20 minutes.

[0077] After the carbon thermal conductive layer is bent and folded and then horizontally pressed, it is stacked in the order of metal heat dissipation layer, connecting layer and carbon thermal conductive layer to obtain a laminate. The laminate is then placed in a vacuum hot press, evacuated to a vacuum degree ≤0.01Pa, heated to 850℃~950℃, and subjected to a pressure of 50MPa~100MPa for 10min~30min. An alloy layer is formed between the connecting layer and the metal heat dissipation layer, and a titanium carbide layer is formed between the connecting layer and the carbon thermal conductive layer.

[0078] A third aspect of this application provides an electronic device, the electronic device including the heat dissipation device as described in the first aspect.

[0079] It should be noted that this application does not impose specific requirements or limitations on the form of the electronic device, and those skilled in the art can make a reasonable choice based on actual usage needs. For example, the electronic device is a mobile phone, and the aforementioned heat dissipation device is disposed on the chip of the mobile phone.

[0080] Example 1

[0081] The surfaces of the metal heat dissipation layer and the connecting layer were polished with 2000-grit silicon carbide sandpaper for 3 minutes each, and then ultrasonically treated in acetone for 10 minutes. The metal heat dissipation layer was a 0.5 mm thick copper layer, and the connecting layer was a 10 μm thick Ag layer. 27 The Cu4Ti layer contains 90.6% Ag by mass, 7.9% copper by mass, and 1.5% titanium by mass.

[0082] After the carbon thermal conductive layer is bent and folded and horizontally pressed in sequence, it is stacked in the order of metal heat dissipation layer, connecting layer and carbon thermal conductive layer to obtain a laminate. The carbon thermal conductive layer is a graphene layer with a thickness of 60 μm. It is placed in a vacuum hot press, evacuated to a vacuum degree of 0.01 Pa, heated to 850 °C, and a pressure of 100 MPa is applied to the laminate and held for 30 min. A titanium-copper alloy layer with a thickness of 3 μm is formed between the connecting layer and the metal heat dissipation layer. A titanium carbide layer with a thickness of 1 μm is formed between the connecting layer and the carbon thermal conductive layer and penetrated into the carbon thermal conductive layer. After the vacuum is removed and the temperature is restored to room temperature, the heat dissipation device is obtained.

[0083] Example 2

[0084] The heat dissipation device was prepared according to the method of Example 1, except that the thickness of the connecting layer was 20 μm, and the thickness of the titanium carbide layer in the prepared heat dissipation device was 3 μm and the thickness of the titanium-copper alloy layer was 5 μm.

[0085] Example 3

[0086] The heat dissipation device was prepared according to the method of Example 2, except that the applied pressure was 50 MPa and the pressure was maintained for 10 min. In the prepared heat dissipation device, the thickness of the titanium carbide layer was 2 μm and the thickness of the titanium-copper alloy layer was 4 μm.

[0087] Example 4

[0088] The heat dissipation device was prepared according to the method of Example 3, except that the heating temperature was 950°C and the thickness of the titanium carbide layer in the prepared heat dissipation device was 2.5 μm and the thickness of the titanium-copper alloy layer was 4.5 μm.

[0089] Example 5

[0090] The heat dissipation device was prepared according to the method of Example 1, except that the thickness of the connecting layer was 5 μm.

[0091] Example 6

[0092] The heat dissipation device was prepared according to the method of Example 1, except that the thickness of the connecting layer was 30 μm.

[0093] Example 7

[0094] The heat dissipation device was prepared according to the method of Example 1, except that the applied pressure was 40 MPa.

[0095] Example 8

[0096] The heat dissipation device was prepared according to the method of Example 1, except that the applied pressure was 120 MPa.

[0097] Example 9

[0098] The heat dissipation device was prepared according to the method of Example 1, except that the heating temperature was 800°C.

[0099] Example 10

[0100] The heat dissipation device was prepared according to the method of Example 1, except that the heating temperature was 1000°C.

[0101] Example 11

[0102] The heat dissipation device was prepared according to the method of Example 1, except that the connecting layer was made of Ag-Cu-Ti alloy with an Ag content of 94.5%, a copper content of 5%, and a titanium content of 0.5%.

[0103] Example 12

[0104] The heat dissipation device was prepared according to the method of Example 1, except that the connecting layer contained 84% Ag, 12% copper, and 4% titanium.

[0105] Comparative Example 1

[0106] The carbon thermal conductive layer and the metal heat dissipation layer from Example 1 are used, and the carbon thermal conductive layer and the metal heat dissipation layer are directly connected by fastening screws.

[0107] Comparative Example 2

[0108] The carbon thermal conductive layer and metal heat dissipation layer from Example 1 are used, and an acrylic tape with a thickness of 10 μm is directly applied to the carbon thermal conductive layer and the metal heat dissipation layer.

[0109] Test case

[0110] The interfacial thermal impedance between the carbonaceous thermally conductive layer and the metal heat dissipation layer in the heat dissipation devices prepared in the above embodiments and comparative examples was tested. The testing method included:

[0111] A side of the heat dissipation device with a carbon thermally conductive layer is connected to a constant-power ceramic heating element with a heating power of 10W. A thermocouple is placed between the carbon thermally conductive layer and the ceramic heating element, and the temperature is recorded as T1. A thermocouple is placed on the surface of the heat dissipation device near the metal heat dissipation layer, and the temperature is recorded as T2. The surface area S of the carbon thermally conductive layer is 100cm². 2 The volume thermal resistance R1 of the carbonaceous thermally conductive layer is 0.1 Kcm. 2 If the interfacial thermal resistance between the carbon thermal conductive layer and the metal heat dissipation layer is R2=(T1-T2)S / W-R1, the test results are shown in Table 1.

[0112] Table 1

[0113]

[0114]

[0115] As can be seen from the table above:

[0116] (1) Compared with Examples 5-6, Example 1 shows that by controlling the thickness of the titanium carbide layer, alloy layer and connecting layer, this application can ensure a stable connection between the metal heat dissipation layer and the carbon heat conduction layer without affecting the heat conduction effect.

[0117] (2) Compared with Examples 7-8, Example 1 shows that by controlling the pressure during the hot pressing process, this application ensures that the connecting layer can form a stable alloy layer and a titanium carbide layer with the metal heat dissipation layer and the carbon thermal conductive layer, respectively. This results in good contact between the connecting layer and both the metal heat dissipation layer and the carbon thermal conductive layer, and has the characteristics of low interfacial thermal resistance. If the pressure is relatively low, the connecting layer may not be able to form sufficient good contact with the metal heat dissipation layer and the carbon thermal conductive layer, resulting in high interfacial thermal resistance. If the pressure is relatively high, as in Example 8, silver overflows from the connecting layer, affecting the connection stability.

[0118] (3) Compared with Examples 9-10, Example 1 shows that the temperature is controlled during the hot pressing process in this application to ensure that the connecting layer forms a stable alloy layer and titanium carbide layer with the metal connecting layer and the carbon thermal conductive layer respectively, thus ensuring connection stability and low interface thermal resistance. If the temperature is relatively low, the connecting layer cannot make sufficient and good contact with the metal heat dissipation layer and the carbon thermal conductive layer, resulting in high interface thermal resistance; if the temperature is relatively high, the metal heat dissipation layer may melt, thereby affecting the connection stability.

[0119] (4) Compared with Examples 11-12, Example 1 shows that the present application controls the content of titanium, metal heat dissipation layer material and fluxing material in the connecting layer to ensure good connection stability between the connecting layer and the metal heat dissipation layer and the carbon heat conduction layer respectively.

[0120] (5) Compared with Comparative Examples 1-2, Example 1 shows that the mixed material layer containing the metal material and titanium in the metal heat dissipation layer used in this application is used as the connecting layer, which can form a stable connection with the metal heat dissipation layer and the carbon thermal conductive layer, and the interface contact is tight, which does not affect the heat dissipation effect. Comparative Example 1 uses a bolt mechanical connection. First, there are obvious pores between the metal heat dissipation layer and the carbon thermal conductive layer, resulting in high interface thermal resistance. Moreover, the mechanical connection easily damages the carbon thermal conductive layer, thus affecting the heat dissipation effect. Comparative Example 2 uses acrylic adhesive to bond the metal heat dissipation layer and the carbon thermal conductive layer. Although it can maintain a good contact effect, the poor thermal conductivity of acrylic adhesive affects the overall heat dissipation effect of the heat dissipation device, with an interface thermal resistance of 0.17 K·cm. 2 With a strength of / W or higher, the interfacial thermal resistance of the heat dissipation device in this application can reach 0.053 K·cm. 2 / W and below.

[0121] Through the above embodiments and comparative examples, this application employs a connecting layer that can bond with the metal heat dissipation layer and the carbon thermal conductive layer. The titanium in the connecting layer can form a titanium carbide layer with the carbon thermal conductive layer, and the metal heat dissipation layer can form a connecting layer with the connecting layer, thereby achieving a stable connection between the metal heat dissipation layer and the carbon thermal conductive layer. Moreover, the interlayer thermal resistance is low, resulting in excellent heat dissipation performance.

[0122] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0123] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A heat dissipation device, characterized in that, The heat dissipation device includes a stacked metal heat dissipation layer, a connecting layer, and a carbon thermally conductive layer. The connecting layer is made of titanium, a metal material contained in the metal heat dissipation layer, and a fluxing material. The connecting layer contains 6% to 10% by mass of the metal material in the metal heat dissipation layer, 1% to 3% by mass of titanium, and 87% to 93% by mass of the fluxing material. The heat dissipation device further includes an alloy layer and a titanium carbide layer, the alloy layer being located between the metal heat dissipation layer and the connecting layer, and the alloy layer being used to connect the metal heat dissipation layer and the connecting layer; The titanium carbide layer is located between the carbonaceous thermally conductive layer and the connecting layer, and the titanium carbide layer is used to connect the carbonaceous thermally conductive layer and the connecting layer; The method for preparing the heat dissipation device includes: The metal heat dissipation layer, the connecting layer, and the carbon thermal conductive layer are sequentially stacked to obtain a laminate. The laminate is then pressurized under heating conditions. The pressure of the pressurization process is 50 MPa to 100 MPa, and the heating temperature is 850°C to 950°C. An alloy layer is formed between the metal heat dissipation layer and the connecting layer, and a titanium carbide layer is formed between the carbon thermal conductive layer and the connecting layer, thus preparing the heat dissipation device.

2. The heat dissipation device as described in claim 1, characterized in that, The carbonaceous thermal conductive layer and the titanium carbide layer are integrally structured, and the metallic titanium in the connecting layer penetrates into the carbonaceous thermal conductive layer to form the titanium carbide layer.

3. The heat dissipation device as described in claim 1, characterized in that, The heat dissipation device satisfies at least one of the following conditions: (1) The material of the carbonaceous thermal conductive layer includes at least one of artificial graphite, natural graphite and graphene; (2) The material of the metal heat dissipation layer includes copper or copper alloy.

4. The heat dissipation device as described in claim 3, characterized in that, The carbonaceous thermally conductive layer has a pleated shape.

5. The heat dissipation device according to any one of claims 1-4, characterized in that, The heat dissipation device satisfies at least one of the following conditions: (1) The thickness of the titanium carbide layer is 1 μm to 3 μm; (2) The thickness of the alloy layer is 3μm to 5μm; (3) The thickness of the connecting layer is 10μm to 20μm.

6. A method for manufacturing the heat dissipation device according to any one of claims 1-5, characterized in that, The preparation method includes: A metal heat dissipation layer, a connecting layer, and a carbon thermally conductive layer are sequentially stacked to obtain a laminate. The laminate is then pressurized under heating conditions. The pressure of the pressurization process is 50 MPa to 100 MPa, and the heating temperature is 850°C to 950°C. An alloy layer is formed between the metal heat dissipation layer and the connecting layer, and a titanium carbide layer is formed between the carbon thermally conductive layer and the connecting layer, thus preparing the heat dissipation device.

7. The preparation method according to claim 6, characterized in that, The preparation method satisfies at least one of the following conditions: (1) The pressurization treatment time is 10 min to 30 min; (2) Both the heating and the pressurization processes are carried out in a vacuum environment.

8. The preparation method according to claim 7, characterized in that, The vacuum level of the vacuum environment is ≤0.01Pa.

9. The preparation method according to claim 6, characterized in that, The preparation method also satisfies at least one of the following conditions: (1) The thickness of the metal heat dissipation layer is 10μm to 50μm; (6) The thickness of the carbon thermal conductive layer is 20μm to 300μm.

10. The preparation method according to any one of claims 6-8, characterized in that, Before being laminated, the carbonaceous thermally conductive layer undergoes bending and pleating treatment and horizontal pressing treatment in sequence.

11. An electronic device, characterized in that, The electronic device includes the heat dissipation device according to any one of claims 1-5.

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