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CN-121975328-A - High-heat-conductivity low-oil-permeability bio-based heat conduction interface material and preparation method thereof

CN121975328ACN 121975328 ACN121975328 ACN 121975328ACN-121975328-A

Abstract

The invention discloses a high-heat-conductivity low-oil-permeability bio-based heat conduction interface material and a preparation method thereof. The material takes organosilicon polymer as a matrix and 260-320 parts by weight of composite heat-conducting filler as a main body, wherein the composite filler comprises (30-50) modified eggshell powder, spherical alumina and flaky boron nitride (40-60) and (5-15), and the surface water contact angle of the modified eggshell powder is larger than 90 degrees after calcination and silane coupling agent treatment. The preparation adopts a three-stage dispersion and auxiliary agent pre-dilution process. The material has the synergistic performance of high heat conduction and ultralow oil seepage through the superhydrophobic surface oil locking mechanism of the modified eggshell powder, and solves the long-term reliability problem of heat dissipation of high-power electronic devices.

Inventors

  • LI LIN

Assignees

  • 浙江锐硅源科技有限公司

Dates

Publication Date
20260505
Application Date
20260210

Claims (7)

  1. 1. The biological-based heat conduction interface material with high heat conduction and low oil seepage is characterized by comprising an organosilicon polymer matrix and a composite heat conduction filler dispersed in the organosilicon polymer matrix, wherein the addition amount of the composite heat conduction filler is 260-320 parts by weight based on 100 parts by weight of the organosilicon polymer matrix, the composite heat conduction filler comprises modified eggshell powder, spherical aluminum oxide and flaky boron nitride, the mass ratio of the modified eggshell powder to the spherical aluminum oxide to the flaky boron nitride is (30-50): (40-60): (5-15), and the mass ratio is calculated by the mass of the modified eggshell powder to the spherical aluminum oxide (sum of fine particle size and coarse particle size) and the flaky boron nitride; the modified eggshell powder is prepared by sequentially calcining eggshell powder and hydrophobizing the surface of a silane coupling agent, wherein the calcining treatment enables the eggshell powder to form a porous structure, and the silylation treatment enables a hydrophobic layer to be formed on the surface of the eggshell powder, so that the surface water contact angle of the modified powder is larger than 90 degrees.
  2. 2. The thermally conductive interface material of claim 1, wherein the calcination treatment is at a temperature of 300-400 ℃ and a calcination time of 15-40 minutes.
  3. 3. The thermally conductive interface material of claim 1 or 2, wherein the silane coupling agent is gamma-glycidoxypropyl trimethoxysilane.
  4. 4. The thermally conductive interface material of claim 1, wherein the spherical alumina is composed of fine grain size alumina and coarse grain size alumina, the fine grain size alumina has a D50 of 3-7 microns, the coarse grain size alumina has a D50 of 25-35 microns, and the mass ratio of fine grain size to coarse grain size alumina is (1.4:1) to (1.6:1).
  5. 5. The thermally conductive interface material of any one of claims 1-4, wherein the silicone polymer matrix is a vinyl silicone oil having a viscosity of 8000-12000 millipascal-seconds.
  6. 6. A method of preparing the thermally conductive interface material of any of claims 1-5, comprising the steps of: S1, mixing an organosilicon polymer matrix, all the modified egg shell powder and all the spherical alumina with fine particle size, and performing first-stage dispersion to form slurry; S2, adding all coarse-grain-diameter spherical alumina and all flaky boron nitride into the slurry, and performing second-stage high-speed dispersion under vacuum and heating conditions to obtain paste; S3, cooling the paste, and then carrying out third-stage vacuum mixing and defoaming with an auxiliary agent system, wherein the auxiliary agent system comprises a cross-linking agent, a catalyst, an inhibitor and an adhesion promoter; and S4, molding and curing the uniformly mixed paste to obtain the heat-conducting interface material.
  7. 7. The method of claim 6, wherein the vacuum degree in the step S2 is not lower than-0.095 MPa, the heating temperature is 40-50 ℃, the high-speed dispersion rotating speed is 1500-3000 rpm, the auxiliary agent system in the step S3 is added by adopting a pre-dilution method, namely, firstly, uniformly mixing a cross-linking agent, an adhesion promoter and an inhibitor in advance, then adding a catalyst, forming a pre-diluted mother solution, and then mixing with the paste, wherein the mixing rotating speed is 800-1500 rpm.

Description

High-heat-conductivity low-oil-permeability bio-based heat conduction interface material and preparation method thereof Technical Field The invention relates to the technical field of electronic chemicals and thermal management materials, in particular to a high-performance heat-conducting interface material for heat dissipation of a high-power electronic device, and especially relates to a heat-conducting gel or paste with high heat conductivity and ultralow oil permeability by taking modified biomass waste as a core functional filler and a preparation method thereof. Background With the continuous increase of power density of electronic devices, efficient heat dissipation has become a key bottleneck restricting performance and reliability. The heat conducting interface material is filled in the micro gap between the heating chip and the radiator to replace air with extremely low heat conductivity and establish efficient heat conducting channel. In order to achieve high thermal conductivity (usually not less than 3.0W/(mK)), the mainstream scheme in the industry relies on the filling of ceramic fillers such as spherical alumina and boron nitride in high proportion into the organosilicon matrix. However, this high fill strategy exacerbates the long-standing industry challenge of severe oil bleed. Under the condition of long-term high-temperature working or thermal cycle, micromolecular silicone oil in an organosilicon matrix is easy to separate out, so that materials are dried up, thermal resistance is increased, peripheral elements can be polluted, and long-term reliability of the device is seriously affected. In order to cope with the oil seepage challenge, the prior art mainly focuses on routes such as modification of a chemical coupling agent, synthesis of a novel matrix polymer, structural design of a composite filler and the like, but has the limitations of limited improvement, high cost or insufficient pertinence and the like. In addition, although biomass fillers (such as eggshell powder) are explored due to low cost, the original eggshell powder has hydrophilic surface, compact structure and poor compatibility with silicone oil, and cannot meet the requirement of high performance. Therefore, development of a novel heat-conducting interface material capable of fundamentally solving the contradiction between high heat conduction and low oil seepage in a synergistic way has urgent need. The applicant has previously developed highly active porous modified eggshell powder (application number: 202511893784X). However, the successful application of the material to the heat conduction interface material with strict comprehensive performance requirements and the inherent contradiction between heat conduction and oil seepage resistance are overcome, and the material is not realized by simple direct replacement. The invention creatively combines the specific modified eggshell powder with spherical alumina and flaky boron nitride with specific types, particle sizes and mass ratio for the first time to construct a synergistic oil locking system special for heat conduction interface materials, and realizes synchronous compromise of ultrahigh heat conduction (more than or equal to 3.0W/(m.K)) and ultralow oil permeability (less than or equal to 0.5 percent at 85 ℃ per 168 h). Disclosure of Invention Object of the invention The invention aims to overcome the defects of serious long-term oil seepage and insufficient reliability of the traditional high-filling heat-conducting interface material, and provides a heat-conducting interface material with high heat conductivity (more than or equal to 3.0W/(m.K)) and ultralow oil seepage rate (less than or equal to 0.5% at 85 ℃ per 168 h) and a preparation method thereof. (II) technical scheme In order to achieve the above purpose, the present invention adopts the following technical scheme: The high-heat-conductivity low-oil-permeability bio-based heat conduction interface material comprises an organosilicon polymer matrix and a composite heat conduction filler dispersed in the organosilicon polymer matrix, wherein the addition amount of the composite heat conduction filler is 260-320 parts by weight based on 100 parts by weight of the organosilicon polymer matrix, the composite heat conduction filler comprises modified egg shell powder, spherical aluminum oxide and flaky boron nitride, the mass ratio of the modified egg shell powder to the spherical aluminum oxide to the flaky boron nitride is (30-50), the mass ratio of the modified egg shell powder to the spherical aluminum oxide to the flaky boron nitride is (40-60), the mass ratio is (5-15), and the mass ratio is calculated by the mass of the modified egg shell powder to the spherical aluminum oxide (sum of fine particle size and coarse particle size) and the flaky boron nitride; the modified eggshell powder is prepared by sequentially calcining eggshell powder and hydrophobizing the surface of a silane coupling agent