Heat-conducting insulating thick adhesive tape as well as preparation method and application thereof

Abstract

The invention discloses a heat-conducting insulating thick adhesive tape which comprises a base layer, a first bonding layer, a graphene layer and a second bonding layer which are sequentially arranged from bottom to top, and the thickness of the heat-conducting insulating thick adhesive tape is 200-600 microns. The invention also provides a preparation method of the heat-conducting insulating thick adhesive tape. The preparation method comprises the following steps: providing an adhesive suspension; coating the surface of one side of the graphene layer with an adhesive suspension, and drying to complete the connection between the first adhesive layer and the graphene layer; adhering the base layer to the surface of one side, far away from the graphene layer, of the first adhesive layer; and coating the surface of one side, far away from the first adhesive layer, of the graphene layer with the adhesive suspension, and drying to complete connection between the second adhesive layer and the graphene layer. When the thickness of the adhesive tape reaches up to 300 microns, the in-plane heat conductivity coefficient exceeds 150 W / mK, the volume resistivity reaches up to 5.07 * 10 < 11 > omega.cm, and the adhesive tape has the characteristics of high comprehensive performance such as high in-plane heat conductivity coefficient, large thickness and excellent electrical insulation performance.

Description

Technical Field

[0001] This invention belongs to the field of thermally conductive adhesive technology, specifically relating to a thermally conductive insulating thick tape, its preparation method, and its application. Background Technology

[0002] With the rapid development of electronic devices and their components, their power consumption and heat flux density have increased significantly. At the same time, the shrinking internal space of compact electronic devices makes it difficult for high-heat-dissipation components (such as high-power chips) to directly contact heat sinks, further exacerbating the heat dissipation problem. To solve this issue, high thermal conductivity materials are often used to connect high-power components to heat sinks. However, such materials often have high conductivity, which may lead to the risk of short circuits. Relevant literature includes: GUO G, LIU Y, DINGY, LIU W, ZHU G, HAO X, HUANG X, XIA J, LI B, ZHANG TY, SUN B. Flexible yet impermeable composites with wrinkle structured BNNSs assembling for high-performance thermal management[J]. npj Flexible Electronics, 2024, 8(1):34. CUIY, QIN Z, WU H, LI M, HU Y. Flexible thermal interface based on self-assembled boron arsenide for high-performance thermal management[J]. Nature Communications, 2021, 12(1):1284.In contrast, polymer-based tapes that combine electrical insulation and thermal conductivity have greater application potential due to their flexibility, ease of processing, and lightweight properties. For example, the literature includes: WU Z, DONG J, GUO H, SHANG R, QINX, XIA Y, LI X, ZHAO X, JI C, ZHANG Q. Robust, Self-Healing, and Multi-Use Poly(Urethane-Urea-Imide) Elastomer as a Durable Adhesive for Thermal Interface Materials[J]. Small, 2024, 20(34): 2401815. XIE Z, DOU Z, WU D, ZENG X, FENG Y, TIAN Y, FU Q, WU K. Joint-Inspired Liquid and Thermal Conductive Interface for Designing Thermal Interface Materials with High Solid Filling yet Excellent Thixotropy[J]. Advanced Functional Materials, 2023, 33(14): 2214071. ZHAN K, CHENY, XIONG Z, ZHANG Y, DING S, ZHEN F, LIU Z, WEIQ, LIU M, SUN B, CHENG HM, QIU L. Lowthermal contact resistance boron nitride nanosheets composites enabled by interfacial arc-like phonon bridge[J]. Nature Communications, 2024, 15(1): 2905. However, it suffers from the drawback of generally low heat transferability (P).

[0003] The definition of heat transfer performance P is Among them κ / / Let t be the in-plane thermal conductivity, w be the thickness, width, and length of the tape, respectively, and T1 and T2 be the temperatures at both ends of the tape. Due to practical industrial needs, the key to improving the heat transfer performance of tapes often lies in optimizing their dimensions and increasing their in-plane thermal conductivity. In the process of realizing this invention, the inventors found that the prior art has at least the following problems: Currently, increasing the thickness of the tape usually leads to a decrease in the in-plane thermal conductivity. For example, the most advanced electrically insulating thermally conductive adhesive material has a thickness of less than 200 μm and an in-plane thermal conductivity of only 60-70 W / m K. (CHEN J, HUANG X, SUN B, JIANG P. Highly Thermally Conductive Yet Electrically Insulating Polymer / Boron Nitride Nanosheets Nanocomposite Films for Improved Thermal Management Capability[J].ACS Nano,2019,13(1):337-45. WANG D, REN S, CHENJ, LI Y, WANG Z, XU J, JIA X, FU J. Healable, highly thermally conductive, flexible polymer composite with excellent mechanical properties and multiple functionalities[J].Chemical Engineering Journal,2022,430:133163. HU Q, BAI X, ZHANG C, ZENG X, HUANG Z, LI J, LI J, ZHANG Y. Oriented BN / Silicone rubber composite thermal interface materials with high out-of-plane thermal conductivity and flexibility[J]. Composites Part A: Applied Science and Manufacturing, 2022, 152: 106681.), the reason is that the intrinsic thermal conductivity of commonly used electrical insulating fillers is inherently low. Furthermore, increased thickness leads to a decrease in tape density and a drop in the thermal diffusivity. The decrease in tape density is mainly due to the "skin effect" caused by the extended drying and evaporation path during solvent removal, as well as the decrease in volume shrinkage during subsequent pressing. With increased tape thickness, the filler contact area decreases, the stacking becomes loose, the shear force decreases, and the filler orientation deteriorates.Develop with high κ. / / Thick, thermally conductive adhesives with excellent electrical insulation properties are one of the key ways to overcome the technical bottlenecks that urgently need to be broken through in the field of electronic heat dissipation. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a thermally conductive and insulating thick tape, its preparation method and application, in order to address the shortcomings of the prior art.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0006] On one hand, a thermally conductive and insulating thick tape is provided, comprising a base layer, a first adhesive layer, a graphene layer, and a second adhesive layer arranged sequentially from bottom to top; the thickness of the thermally conductive and insulating thick tape is 200 to 600 micrometers.

[0007] On the other hand, a method for preparing the above-mentioned thermally conductive and insulating thick adhesive tape is provided, comprising:

[0008] Provide adhesive suspension;

[0009] The adhesive suspension is coated on one side of the graphene layer and dried to complete the connection between the first adhesive layer and the graphene layer.

[0010] The base layer is adhered to the side of the first adhesive layer away from the graphene layer;

[0011] The adhesive suspension is coated on the side of the graphene layer away from the first adhesive layer and dried to complete the connection between the second adhesive layer and the graphene layer.

[0012] On the other hand, this invention provides an application of the aforementioned thermally conductive and insulating thick tape in heat dissipation of electronic devices.

[0013] Compared with the prior art, the present invention has the following advantages:

[0014] 1. This invention provides a thermally conductive and insulating thick tape comprising a multilayer structure consisting of a base layer, a first adhesive layer, a graphene layer, and a second adhesive layer connected in series. This structure fully leverages the ultra-high thermal conductivity of the graphene layer, the low contact thermal resistance of the adhesive layer, and the high insulation performance of the adhesive layer and the base layer. At a thickness of up to 300 micrometers, the in-plane thermal conductivity exceeds 150 W / m K, and the volume resistivity reaches 5.07 × 10⁻⁶. 11 Ω·cm, achieving a combination of high in-plane thermal conductivity, large thickness and excellent electrical insulation performance.

[0015] 2. This invention provides a method for preparing a thermally conductive and insulating thick tape, preferably by scraping to achieve the setting of the adhesive layer on the graphene layer, which is simple and efficient.

[0016] 3. This invention provides a continuous preparation method for thermally conductive and insulating thick tape, which has the characteristics of excellent comprehensive performance, high production efficiency and high yield, and is suitable for promotion and application in the consumer electronics market.

[0017] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the multilayer structure of the thermally conductive and insulating thick tape in Example 1;

[0019] Figure 2 The structural formula of the acrylate polymer in Example 1 is shown below;

[0020] Figure 3 Here is a scanning electron microscope image of the thermally conductive insulating thick tape of Example 1;

[0021] Figure 4 An optical photograph of the thermally conductive insulating thick tape of Example 1;

[0022] Figure 5 Image a is a scanning electron microscope image of boron nitride nanosheets from Example 1; Figure 5 b is a scanning electron microscope image of BN (boron nitride microsheets) in the substrate of Example 1.

[0023] Explanation of reference numerals in the attached figures

[0024] 1-Base layer; 2-First adhesive layer;

[0025] 2-Graphene layer; 4-Second adhesive layer. Detailed Implementation

[0026] The technical solution will now be clearly and completely described with reference to the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0027] In the following description, the term "and / or" is used to describe the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, B exists alone, and A and B exist simultaneously. A and B can be singular or plural.

[0028] In the following description, the terms “including,” “containing,” “having,” and “containing” are open-ended terms, meaning that they include but are not limited to.

[0029] Those skilled in the art should understand that, in the following description of the embodiments of this application, the sequence of numbers does not imply the order of execution. Some or all steps may be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0030] Those skilled in the art will understand that the numerical ranges in the embodiments of this application should be understood to specifically disclose each intermediate value between the upper and lower limits of the range. Each smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this application. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0031] Unless otherwise stated, the technical / scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. While this application describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this application. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0032] The technical principle adopted in this invention is as follows: by setting up a base layer, a first adhesive layer, a graphene layer, and a second adhesive layer, the ultra-high thermal conductivity of the graphene layer, the low contact thermal resistance of the adhesive layer, and the high electrical insulation properties of the adhesive layer and the base layer are fully activated. The synergistic cooperation of each layer structure endows the tape with high in-plane thermal conductivity on a relatively thick basis. The in-plane thermal conductivity can be greatly improved without improving the filler size and filler amount, thus obtaining a tape with both high heat transfer performance and insulation properties.

[0033] On one hand, a thermally conductive and insulating thick tape is provided, comprising a base layer, a first adhesive layer, a graphene layer, and a second adhesive layer arranged sequentially from bottom to top; the thickness of the thermally conductive and insulating thick tape is 200 to 600 micrometers.

[0034] This invention provides a thermally conductive and insulating thick tape, composed of a base layer, a first adhesive layer, a graphene layer, and a second adhesive layer arranged sequentially, with a thickness of 200-600 micrometers, far exceeding the thickness of existing tapes less than 200 micrometers. At a thickness of 300 micrometers, the in-plane thermal conductivity of the tape exceeds 150 W / m K, and the volume resistivity is above 10⁻⁶. 11 It is power-order and has excellent electrical insulation properties.

[0035] In some embodiments, the thickness of the base layer, the first adhesive layer, the graphene layer, and the second adhesive layer are all 40 to 200 micrometers.

[0036] In some embodiments, the in-plane thermal conductivity of the graphene layer is >500 W / m K.

[0037] This invention uses graphene paper with ultra-high thermal conductivity as a functional layer, which works in conjunction with the adhesive layer and the base layer to give the tape high heat transfer performance.

[0038] In some embodiments, the raw materials of both the first and second adhesive layers include ceramic filler, adhesive matrix, and solvent; the mass ratio of the ceramic filler, adhesive matrix, and solvent is (0.1–2):(8–10):15; the ceramic filler includes one or more of hexagonal boron nitride, boron nitride nanosheets, and aluminum nitride; the adhesive matrix includes polyacrylate, polyimide, or epoxy resin; and the solvent includes one or more of N,N-dimethylacetamide, ethyl acetate, and acetone. In some preferred embodiments, the ceramic filler is boron nitride nanosheets, and the mass ratio of the ceramic filler, adhesive matrix, and solvent is (0.5–1):(9–9.5):15; more preferably, the mass ratio of the ceramic filler, adhesive matrix, and solvent is 1:9:15.

[0039] The present invention uses the above-mentioned raw materials containing ceramic filler, binder matrix and solvent as adhesive layer raw materials to reduce interlayer thermal resistance.

[0040] In some embodiments, the base layer is ceramic silicone rubber, wherein the ceramic component comprises one or more of boron nitride, aluminum nitride, and silicon carbide. In some preferred embodiments, the ceramic component comprises boron nitride, or is a mixture of aluminum nitride and silicon carbide.

[0041] On the other hand, a method for preparing the above-mentioned thermally conductive and insulating thick adhesive tape is provided, comprising:

[0042] Provide adhesive suspension;

[0043] The adhesive suspension is coated on one side of the graphene layer and dried to complete the connection between the first adhesive layer and the graphene layer.

[0044] The base layer is adhered to the side of the first adhesive layer away from the graphene layer;

[0045] The adhesive suspension is coated on the side of the graphene layer away from the first adhesive layer and dried to complete the connection between the second adhesive layer and the graphene layer.

[0046] This invention provides a method for preparing the above-mentioned thermally conductive and insulating thick tape, which includes first connecting a first adhesive layer to a graphene layer, connecting a base layer to the first adhesive layer, and then connecting a second adhesive layer to the graphene layer, thereby realizing the effective series connection of a multi-layer structure and obtaining an insulating tape with high thickness and high heat transfer performance.

[0047] In some embodiments, providing the adhesive suspension specifically includes: mixing adhesive suspension raw materials, and then alternating between magnetic stirring and ultrasonic dispersion to obtain the adhesive suspension; the number of times for both magnetic stirring and ultrasonic dispersion is twice; the stirring rate for magnetic stirring is 500 rpm and the stirring time is 10 to 600 minutes; the power for ultrasonic dispersion is 100 W, the frequency is 30 kHz, and the ultrasonic dispersion time is 10 to 600 minutes.

[0048] In some embodiments, the drying after coating the adhesive suspension on one side of the graphene layer and on the side of the graphene layer away from the first adhesive layer is a programmed drying process, which includes: holding at room temperature for 2 hours, heating to 40°C at a heating rate of 1 to 5°C / min and holding for 2 hours, and heating to 60°C at a heating rate of 1 to 5°C / min and holding for 8 hours.

[0049] In some preferred embodiments, the adhesive suspension is obtained by alternating magnetic stirring and ultrasonic dispersion, and the solvent is removed by programmed drying. This can effectively avoid the density reduction caused by the mismatch between the surface solvent evaporation rate and the internal solvent evaporation rate, as well as the loose stacking of fillers, and obtain a thermally conductive and insulating thick tape with uniform texture and high consistency.

[0050] In some specific embodiments, the coating includes blade coating, spin coating, or spray coating. In some preferred embodiments, the coating is blade coating.

[0051] Furthermore, a method for continuously preparing the above-mentioned thermally conductive and insulating thick tape is provided, comprising:

[0052] Using a roll-to-roll coating machine, an adhesive suspension is coated onto the graphene roll material;

[0053] Drying is carried out through an infrared drying tunnel;

[0054] The base layer is attached to the dried roll material by using hot press rollers;

[0055] Using a roll-to-roll coating machine, an adhesive suspension is applied in reverse to the graphene roll material;

[0056] Drying is performed through an infrared drying tunnel.

[0057] This invention provides a method for continuously preparing the above-mentioned thermally conductive and insulating thick tape, comprising coating an adhesive suspension with a roll-to-roll coating machine and drying it with an infrared drying tunnel, and pressing and connecting the base layer with a hot press roller. The thermally conductive and insulating thick tape obtained by continuous preparation has a high in-plane thermal conductivity, high production efficiency, and a yield rate of over 98%.

[0058] In some embodiments, the infrared drying is hot air-assisted infrared drying, with a drying temperature of 60°C and a wind speed of 2 m / s.

[0059] In some preferred embodiments, the method for continuously preparing the above-mentioned thermally conductive and insulating thick tape involves drying with hot air-assisted infrared radiation, which can effectively break through the surface layer of the adhesive suspension solvent, improve the internal fluidity of the solvent during the drying and solvent removal process, avoid the influence of the "skin effect", and provide a substrate with uniform texture for subsequent rolling.

[0060] On the other hand, this invention provides an application of the aforementioned thermally conductive and insulating thick tape in heat dissipation of electronic devices.

[0061] Prior to this application, a series of experiments were conducted. Some of the experimental results are listed below to provide a more detailed description of the invention. The following is a detailed description in conjunction with the embodiments.

[0062] Example 1

[0063] This embodiment provides a thermally conductive and insulating thick tape with a thickness of 300μm, and its structure is as follows: Figure 1 As shown, from bottom to top, it includes: base layer 1, first adhesive layer 2, graphene layer 3, and second adhesive layer 4; the thickness of the first adhesive layer 2 is 50μm, the thickness of the graphene layer 3 is 100μm, the thickness of the second adhesive layer 4 is 50μm, and the thickness of the base layer 1 is 100μm.

[0064] This embodiment also provides a method for preparing the above-mentioned thermally conductive and insulating thick tape, including:

[0065] Step 1: Under normal temperature conditions, 1g of boron nitride nanosheets (BNNS), 9g of acrylate polymer, and 15g of DMAC were mixed, magnetically stirred for 15min, ultrasonically dispersed for 15min, then magnetically stirred for 15min, and ultrasonically dispersed for 15min to obtain an adhesive suspension. The magnetic stirring speed was 500rpm, and the ultrasonic dispersion power and frequency were 100W and 30kHz. The boron nitride nanosheets were self-made, obtained by ultrasonic-high pressure homogenization after exfoliating commercial boron nitride (Dandong Chemical, HSL36). The acrylate polymer was poly(2-[[(butylamino)carbonyl]oxo]ethyl acrylate], with the structural formula shown below. Figure 2 As shown, the number-average molecular weight is 100,000 to 200,000;

[0066] Step 2: According to the preset first adhesive layer thickness, use a 400μm scraper to apply the adhesive suspension to one side of the graphene paper. Place it in a fume hood and dry at room temperature for 2 hours. Then place it in a vacuum drying oven and heat it to 40℃ at a rate of 2℃ / min and hold for 2 hours. Next, heat it to 60℃ at a rate of 2℃ / min and hold for 8 hours. Allow it to cool naturally to room temperature to complete the connection between the first adhesive layer and the graphene layer. / / Located at 500-600 W / m K, supplied by Hangzhou Gaoxi;

[0067] Step 3: Take out the dried material and attach the base layer to the side of the first adhesive layer away from the graphene layer. Roll it repeatedly 5 times with a 2kg rubber roller. The base layer is a BN / SR material, which is made by mixing BN (Dandong Chemical, HSL36) and silicone rubber (SR) precursor (Dow Corning, Sylgard 184) at a mass ratio of 70:30 and hot pressing it at 100℃ and 10MPa. The thickness of the base layer is 100μm.

[0068] Step 4: According to the preset thickness of the second adhesive layer, use a 600μm scraper to apply the adhesive suspension to the side of the graphene paper away from the first adhesive layer. Place it in a fume hood and dry at room temperature for 2 hours. Then place it in a vacuum drying oven and heat it to 40℃ at a heating rate of 2℃ / min and hold for 2 hours. Then heat it to 60℃ at a heating rate of 2℃ / min and hold for 8 hours. Allow it to cool naturally to room temperature to complete the connection between the second adhesive layer and the graphene layer.

[0069] Example 2

[0070] This embodiment provides a method for preparing a thermally conductive and insulating thick tape, which is the same as in Example 1, except that in step one, the masses of boron nitride nanosheets, acrylate polymers and DMAC are 0.5g, 9.5g and 15g, respectively.

[0071] Example 3

[0072] This embodiment provides a method for preparing a thermally conductive and insulating thick adhesive tape, which is the same as in Embodiment 1, except that step one involves mixing boron nitride nanosheets (1g), epoxy resin, and ethyl acetate in a mass ratio of 1:9:15 to obtain an adhesive suspension; the epoxy resin is of the DURALCO type. TM 4538, Shore A hardness is 60-80, manufacturer is COTRONICS, USA.

[0073] Example 4

[0074] This embodiment provides a method for preparing a thermally conductive and insulating thick tape, which is the same as in Embodiment 1, except that...

[0075] Step one is to mix boron nitride nanosheets (1g), polyimide adhesive and DMAC in a mass ratio of 1:9:15 to obtain an adhesive suspension; the polyimide is SG120L, with a solid content of 5-30%, and is manufactured by Hangzhou Sumengte.

[0076] The base layer in step three is AlN / SiC filled silicone rubber with a filling amount of 50-80%; the AlN is TA-F series with a particle size (D50) of 20-90μm, purchased from Baitu Technology; the SiC is SiC nanowire with a diameter of 0.1-0.5μm and a length of 20-50μm, purchased from Xuzhou Jiechuang.

[0077] Example 5

[0078] This embodiment provides a continuous production process for thermally conductive and insulating thick tape, including:

[0079] According to the preset first adhesive layer thickness, the adhesive suspension shown in Example 1 is applied using a roll-to-roll coating machine at a coating speed of 20 cm / min. -1 It is continuously and uniformly coated onto the graphene roll material;

[0080] The coated roll material was passed through an infrared drying tunnel at 60°C and a wind speed of 2 m / s; the infrared wavelength was 1.5–3 μm, and the material movement speed was 20 cm / min. -1 ;

[0081] BN / SR and the dried roll material are bonded together by pressing them together with a hot press roller at 100°C and 0.3MPa.

[0082] According to the preset second adhesive layer thickness, the adhesive suspension shown in Example 1 was reverse-coated onto the graphene roll using a roll-to-roll coating machine; the coating speed was 20 cm / min. -1 ;

[0083] The reverse-coated roll material was passed through an infrared drying tunnel at 60°C and a wind speed of 2 m / s; the infrared wavelength was 1.5–3 μm, and the material movement speed was 20 cm / min. -1 ;

[0084] Roll it up and cut it.

[0085] Comparative Example 1

[0086] This comparative example examines the effect of adhesive layer raw materials on the performance of the resulting tape. The preparation method is the same as in Example 1, except that...

[0087] Step one involves mixing 1g of boron nitride nanosheets, 9g of acrylate polymers, and 15g of DMAC, and magnetically stirring for 60 minutes to obtain an adhesive layer suspension.

[0088] Comparative Example 2

[0089] This comparative example examines the effect of the adhesive layer preparation process on the performance of the resulting tape. The preparation method is the same as in Example 1, except that...

[0090] Step 1 involves mixing 1g of boron nitride nanosheets, 9g of acrylate polymers, and 15g of DMAC, and magnetically stirring for 60 minutes to obtain an adhesive layer suspension.

[0091] Step two involves applying the adhesive suspension to one side of the graphene paper using a 400μm scraper, according to the preset thickness of the first adhesive layer, and then drying it in a 60℃ vacuum drying oven for 12 hours to complete the connection between the first adhesive layer and the graphene layer.

[0092] Step four involves applying the adhesive suspension to the side of the graphene paper away from the first adhesive layer using a 600μm scraper, according to the preset thickness of the second adhesive layer. The paper is then placed in a vacuum drying oven at 60℃ and dried for 12 hours to complete the connection between the second adhesive layer and the graphene layer.

[0093] Performance Evaluation

[0094] Scanning electron microscope images of the thermally conductive insulating thick tape of Example 1 are shown below. Figure 3 As shown, according to Figure 3 As can be seen, the thermally conductive tape has a multi-layer structure, which is consistent with the structure of the present invention, which includes a base layer, a first adhesive layer, a graphene layer, and a second adhesive layer.

[0095] Optical photograph of the thermally conductive insulating thick tape of Example 1 is shown below. Figure 4 As shown, the thermally conductive insulating thick tape of the present invention has good cutability and bendability.

[0096] Figure 5 Image a is a scanning electron microscope image of the boron nitride nanosheets from Example 1, based on... Figure 5 As can be seen from a, the average planar size of the boron nitride nanosheets is 2 μm.

[0097] Figure 5 b is a scanning electron microscope image of BN (boron nitride microsheets) in the substrate of Example 1, according to Figure 5 As can be seen from b, the average planar size of boron nitride is 21 μm.

[0098] In the following performance tests, κ / / The volume resistivity was obtained according to ASTM E1461 standard, and the test voltage was 100V. The characteristic breakdown strength was obtained according to ASTM D257 standard.

[0099] The results were obtained from the ASTM D149 standard test.

[0100] Example 1: κ of thermally conductive insulating thick tape / / Up to 153.23 W·m -1 • K-1, under a test voltage of 100V, the volume resistivity of this tape reaches 5.07×10⁻⁶. 11 The material exhibits excellent pressure resistance, with a characteristic breakdown strength of 36.9 kV / mm. After aging at 120°C for 100 hours, its thermal conductivity retention rate is 98.6%.

[0101] To verify the performance of the thermally conductive and insulating thick tape in practical applications, a systematic application test was conducted on the thermally conductive and insulating thick tape of Example 1. In the ultra-thin laptop heat dissipation test, the test environment was controlled at a room temperature of 25±1℃, and the laptop CPU was subjected to a full-load test using AIDA64 Extreme software. First, the CPU equilibrium temperature was recorded without the tape. Then, the tape was installed between the CPU's heat dissipation modules, and the test was conducted again under the same operating conditions, and the equilibrium temperature was recorded. The test results showed that the CPU temperature could be reduced by 9℃ after using the tape.

[0102] The thermal performance test for the smartphone SoC was also conducted at a room temperature of 25±1℃. To evaluate the impact of this material on video playback stability, 3DMark software was used to loop the benchmark test video 20 times, and the video frame rate was accurately recorded for each loop. The test data shows that when the thermally conductive insulating thick tape (90mm long and 30mm wide) of Example 1 is placed between the internal components of the phone and the back cover, mainly covering the entire area of ​​the phone SoC and part of the battery area, the video frame rate fluctuation can be controlled within 1%, indicating that the thermally conductive insulating thick tape of the present invention can significantly improve the stability of video playback.

[0103] Example 2 Thermally conductive insulating thick tape κ / / The value was 128.65 W / m K, which is about 26% lower than that of Example 1, and the volume resistivity at 100V was 4.2 × 10⁻⁶. 11 The Ω·cm value decreased slightly, and the characteristic breakdown strength was 32.5 kV / mm². -1 Compared with Example 1, it can be seen that reducing the BNNS content leads to a significant decrease in the thermal conductivity and mechanical strength of the tape, but the insulation performance still meets the basic requirements.

[0104] Example 3 Thermally conductive insulating thick tape κ / / The value was 145.8 W / m K, a 7% decrease compared to Example 1, and the volume resistivity at 100 V was 5.5 × 10⁻⁶. 11The thermal conductivity (Ω·cm) was slightly improved. After aging at 120℃ for 100 hours, the thermal conductivity retention rate was >95%, indicating that the epoxy resin-based adhesive layer has better high-temperature stability and is suitable for high-temperature electronic devices (such as automotive electronics).

[0105] The thermally conductive insulating thick tape of Example 4 / / It has a value of 160.4 W / m K and a volume resistivity of 4.2 × 10⁻⁶ at 100 V. 11 The Ω·cm is slightly lower than that of Example 1, and the characteristic breakdown strength is 45 kV / mm². -1 The thermal conductivity decreases by less than 3% after high-temperature aging (200℃, 500h). This material is suitable for high-temperature and high-power applications such as new energy vehicles and photovoltaic inverters.

[0106] Example 5: Continuously fabricated thermally conductive insulating thick tape (κ) / / The efficiency is 150.1 W / m K, comparable to Example 1, with a production efficiency of 5 m / min and a yield rate >98%. This invention enables low-cost, high-efficiency mass production of thermally conductive insulating thick tape, meeting the demands of the consumer electronics market.

[0107] κ of the thermally conductive insulating thick tape in Comparative Example 1 / / The value was 121.22 W / m K, significantly lower than that of Example 1, and the volume resistivity at 100 V was 5.16 × 10⁻⁶. 11 Ω·cm, characteristic breakdown strength is 35.6kV / mm². -1 After aging at 120°C for 100 hours, the thermal conductivity retention rate was 86%, which is about 12% lower than that of Example 1. The tape in Comparative Example 2... / / It has a strength of 117.42 W / m K and a volume resistivity of 6.18 × 10⁻⁶ at 100 V. 11 Ω·cm, characteristic breakdown strength is 41.1kV / mm -1 It can be seen that the present invention comprises a thermally conductive and insulating thick tape prepared by using boron nitride nanosheets, acrylate polymers and DMAC as binder raw materials and combined with a programmed drying process, which has significantly improved electrochemical performance.

Claims

1. A thermally conductive and insulating thick tape, characterized in that, It includes, from bottom to top, a base layer, a first adhesive layer, a graphene layer, and a second adhesive layer; the thickness of the thermally conductive and insulating thick tape is 200–600 micrometers.

2. The thermally conductive and insulating thick tape according to claim 1, characterized in that, The thickness of the base layer, the first adhesive layer, the graphene layer, and the second adhesive layer are all 40 to 200 micrometers; and / or, the in-plane thermal conductivity of the graphene layer is >500 W / mK.

3. The thermally conductive and insulating thick tape according to claim 1, characterized in that, The raw materials of the first adhesive layer and the second adhesive layer both include ceramic filler, adhesive matrix and solvent; the mass ratio of the ceramic filler, adhesive matrix and solvent is (0.1~2):(8~10):15; and / or, the base layer is ceramic silicone rubber, wherein the ceramic in the ceramic silicone rubber includes one or more of boron nitride, aluminum nitride and silicon carbide.

4. The thermally conductive and insulating thick tape according to claim 3, characterized in that, The ceramic filler includes one or more of hexagonal boron nitride, boron nitride nanosheets, and aluminum nitride; the binder matrix includes polyacrylate, polyimide, or epoxy resin; the solvent includes one or more of N,N-dimethylacetamide, ethyl acetate, and acetone; and / or, the ceramic in the ceramic silicone rubber is boron nitride, or both aluminum nitride and silicon carbide.

5. The thermally conductive and insulating thick tape according to claim 4, characterized in that, The ceramic filler is boron nitride nanosheets, and the mass ratio of the ceramic filler, binder matrix and solvent is (0.5-1):(9-9.5):

15.

6. A method for preparing the thermally conductive and insulating thick tape as described in claim 1, characterized in that, include: Provide adhesive suspension; The adhesive suspension is coated on one side of the graphene layer and dried to complete the connection between the first adhesive layer and the graphene layer. The base layer is adhered to the side of the first adhesive layer away from the graphene layer; The adhesive suspension is coated on the side of the graphene layer away from the first adhesive layer and dried to complete the connection between the second adhesive layer and the graphene layer.

7. The method according to claim 6, characterized in that, The provision of the adhesive suspension specifically includes: mixing adhesive suspension raw materials, alternating magnetic stirring and ultrasonic dispersion to obtain the adhesive suspension; and / or, both the drying after coating the adhesive suspension on one side of the graphene layer and the drying after coating the adhesive suspension on the side of the graphene layer away from the first adhesive layer are procedural drying processes.

8. A method for continuous preparation of the thermally conductive and insulating thick tape as described in claim 1, characterized in that, include: Using a roll-to-roll coating machine, an adhesive suspension is coated onto the graphene roll material; Drying is carried out through an infrared drying tunnel; The base layer is attached to the dried roll material by using hot press rollers; Using a roll-to-roll coating machine, an adhesive suspension is applied in reverse to the graphene roll material; Drying is performed through an infrared drying tunnel.

9. The method according to claim 8, characterized in that, The infrared drying is hot air-assisted infrared drying, with a drying temperature of 60℃ and a wind speed of 2m / s.

10. The application of the thermally conductive insulating thick tape as described in claim 1 in heat dissipation of electronic devices.

Images