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CN-121975269-A - High-temperature-resistant low-thermal-expansion epoxy resin composite material and preparation method thereof

CN121975269ACN 121975269 ACN121975269 ACN 121975269ACN-121975269-A

Abstract

The invention discloses a high-temperature-resistant low-thermal-expansion epoxy resin composite material and a preparation method thereof, belongs to the technical field of high-molecular composite materials and solid electronic packaging, and aims to solve the problems that a high-thermal-conductivity packaging system is easy to crack due to thermal expansion mismatch and breakdown is caused by free catalyst of a conventional dynamic covalent bond material. The composite material is prepared from the following raw materials of tetra-aromatic ring rigid liquid crystal orientation type epoxy resin, a curing agent, a curing accelerator, a solid supported catalyst auxiliary agent and a heat conducting filler. The epoxy resin realizes high-efficiency heat conduction and low thermal expansion through molecular chain rigidity and long-range order orientation. The immobilized catalyst auxiliary agent is prepared by covalent grafting of organic alkali on the surface of a mesoporous inorganic carrier and hydrophobic treatment, so that local fixation is realized, stress is relieved in the curing process, charge conduction caused by catalyst migration is prevented, and the insulation reliability of the material is improved. The invention is applied to power modules such as vehicle-mounted chips, wide bandgap semiconductors and the like.

Inventors

  • ZHANG CHENGLONG
  • HOU YUNXIA
  • LI JIE

Assignees

  • 佛山市新铂桥电子有限公司

Dates

Publication Date
20260505
Application Date
20260323

Claims (10)

  1. 1. The epoxy resin composite material is characterized by comprising, by weight, 60-100 parts of four-aromatic-ring rigid liquid crystal oriented epoxy resin, 35-55 parts of a curing agent, 0.1-0.5 part of a curing accelerator, 3-5 parts of a supported catalyst auxiliary agent and 300-400 parts of a heat conducting filler, wherein the supported catalyst auxiliary agent is FDU12-g-TBD, and consists of FDU-12 mesoporous silica and 1,5, 7-triazabicyclo [4.4.0] dec-5-ene groups covalently bonded to the surface of the FDU-12 mesoporous silica, and the four-aromatic-ring rigid liquid crystal oriented epoxy resin has the molecular structure: 。
  2. 2. The high-temperature-resistant low-thermal expansion epoxy resin composite material as claimed in claim 1, wherein the preparation method of the tetra-aromatic ring rigid liquid crystal alignment epoxy resin comprises the steps of taking 4,4' -biphenol, adding a tetrahydrofuran solvent of triethylamine, cooling to 0 ℃, then dropwise adding a tetrahydrofuran solution of parahydroxybenzoyl chloride, heating to room temperature for reaction for 12 hours after the dropwise adding is finished, precipitating the reaction solution by ice water, filtering, washing with water, and recrystallizing to obtain a molecular intermediate containing a central biaromatic ester bond, then dissolving the intermediate in tetrahydrofuran, adding epichlorohydrin and tetramethyl ammonium bromide, heating to 60-70 ℃ under the condition of stirring for pre-reaction for 1-2 hours, then dropwise adding a sodium hydroxide aqueous solution in batches under the condition of maintaining the reaction temperature, gradually heating to 90 ℃ for continuous reaction for 3-5 hours after the dropwise adding is finished, washing with water, separating an organic phase, drying, and removing the solvent by spin evaporation to obtain the tetra-aromatic ring rigid liquid crystal alignment epoxy resin.
  3. 3. The high temperature resistant low thermal expansion epoxy resin composite material according to claim 2, wherein the molar equivalent ratio of said 4,4' -biphenol, said triethylamine and said parahydroxybenzoyl chloride is 1.0:2.5:2.2, the molar equivalent ratio of said molecular intermediate of central biaromatic ester linkage, said epichlorohydrin and said tetramethylammonium bromide is 1.0:10.0:0.15, the concentration of said aqueous sodium hydroxide solution is 40wt%, and the molar equivalent ratio of said molar equivalent of sodium hydroxide to said molecular intermediate of central biaromatic ester linkage is 2.6:1.0.
  4. 4. The high-temperature resistant low-thermal expansion epoxy resin composite material as claimed in claim 1, wherein the preparation method of the FDU12-g-TBD is characterized in that 1,5, 7-triazabicyclo [4.4.0] dec-5-ene is dissolved in anhydrous toluene, 3-isocyanatopropyl) triethoxysilane is dropwise added under stirring, after the dropwise addition is finished, the system is heated to 50 ℃ and reacts for 6 hours to prepare a silanized 1,5, 7-triazabicyclo [4.4.0] dec-5-ene precursor solution, dehydrated and dried FDU-12 mesoporous silica powder is added into the precursor solution, anhydrous toluene is added to enable the system to form uniform suspension, then constant temperature reflux stirring is carried out for 24 hours at the temperature of 110 ℃, the reaction suspension is cooled to room temperature, hexamethyldisilazane is added and is subjected to closed stirring reaction for 4 hours, the FDmaterial after the reaction is finished is subjected to suction filtration, solid products are collected, soxhlet extraction is carried out for 24-48 hours, and then the solid products are subjected to Soxhlet extraction and drying and the solid products are subjected to vacuum grinding treatment, and the FDU 12-TBD is obtained.
  5. 5. The high-temperature-resistant low-thermal-expansion epoxy resin composite material according to claim 4, wherein the molar equivalent ratio of the 1,5, 7-triazabicyclo [4.4.0] dec-5-ene to the (3-isocyanatopropyl) triethoxysilane is 1.0:1.1, the feeding amount of the FDU-12 mesoporous silica powder is 1 millimole of 1,5, 7-triazabicyclo [4.4.0] dec-5-ene per 1 millimole, 3-4g of carrier powder is correspondingly added, and the solvent used for Soxhlet extraction is a mixed solution of anhydrous toluene and anhydrous ethanol, and the volume ratio is 1:1.
  6. 6. The high-temperature-resistant low-thermal-expansion epoxy resin composite material as claimed in claim 1, wherein the curing agent is an anhydride curing agent comprising methyl hexahydrophthalic anhydride or hexahydrophthalic anhydride, the curing accelerator is 2-ethyl-4-methylimidazole, imidazole or N, N-dimethylbenzylamine, and the heat-conducting filler is spherical alumina or spherical silica micropowder with the surface being subjected to phenyl trimethoxysilane treatment in advance.
  7. 7. The method for preparing the high-temperature-resistant low-thermal-expansion epoxy resin composite material according to any one of claims 1 to 6, which is characterized by comprising the following steps: S1, heating, melting and reducing the viscosity of the pre-dried and crushed tetra-aromatic ring rigid liquid crystal oriented epoxy resin to be liquid phase, sequentially adding the curing agent, the curing accelerator and the immobilized catalyst auxiliary agent, and stirring at a gentle and uniform speed to obtain a premix; S2, adding the heat-conducting filler into the premix liquid in batches under a constant temperature state, and after the heat-conducting filler is infiltrated, carrying out defoaming and dispersing treatment under the synergistic effect of reduced pressure vacuumizing and high-speed shearing so as to obtain uniform and stable composite glue liquid; and S3, carrying out flow control encapsulation treatment on the composite glue solution, heating by adopting a three-stage step type solidification network molding process, and naturally cooling to room temperature to obtain the high-temperature-resistant low-thermal expansion epoxy resin composite material.
  8. 8. The high temperature resistant low thermal expansion epoxy resin composite material according to claim 7, wherein the temperature of the heating and melting in the step S1 is 110 ℃, the rotation speed of gentle uniform stirring is 80-100rpm, and the stirring time is 20 minutes.
  9. 9. The high temperature resistant low thermal expansion epoxy resin composite material according to claim 7, wherein in step S2, the constant temperature is 100 ℃, the pressure of the decompression and vacuum pumping is controlled to be 500-1000Pa, and the rotating speed of the high-rotating-speed shearing is 800-1200rpm.
  10. 10. The high temperature resistant low thermal expansion epoxy resin composite according to claim 7, wherein said three-stage step curing in step S3 is carried out in a first stage at 100-105 ℃ for 2 hours, a second stage at 150-155 ℃ for 2 hours, and a third stage at 200-205 ℃ for 2 hours.

Description

High-temperature-resistant low-thermal-expansion epoxy resin composite material and preparation method thereof Technical Field The invention belongs to the technical field of polymer composite materials and solid electronic packaging, and particularly relates to a high-temperature-resistant low-thermal-expansion epoxy resin composite material and a preparation method thereof. Background Along with the rapid development of the third generation wide bandgap semiconductor power module towards high voltage, high frequency and high power density, the junction temperature requirement on the device is higher and higher. Under the extreme working condition, the packaging material has extremely high thermal conductivity to emit huge heat, and meanwhile, extremely low thermal expansion coefficient is required to match the chip and the copper-clad ceramic substrate, so that interface debonding caused by thermal stress is prevented. The existing electronic packaging composite material mostly adopts bisphenol A type or o-cresol formaldehyde type epoxy resin, and the thermal conductivity is improved and the thermal expansion coefficient is reduced by filling a large amount of inorganic powder. However, high loading can lead to a sharp rise in matrix modulus, the material loses stress buffering capacity, and micro-nano pores or even macro-cracks are very easy to generate at the interface of the resin and the filler under cold and hot impact. The prior art CN116178895A discloses a high heat conduction epoxy resin composite material and a preparation method thereof, wherein a boron nitride-carbon hybridization heat conduction network with a three-dimensional framework structure is obtained by calcining a mixture of boron nitride and polyvinyl alcohol at high temperature, and then the mixture is impregnated with epoxy resin for curing and molding. Although the technology remarkably improves the heat conduction coefficient by constructing a continuous static heat conduction channel, under the actual power module packaging scene, on one hand, the skeleton preparation involves the carbonization process of polyvinyl alcohol, the generated boron nitride-carbon hybridization network inevitably introduces a carbon component with semiconductor characteristics, under the working condition of a strong electric field, the carbon residue is extremely easy to induce leakage current increase and dielectric loss increase, and the requirement of a high-voltage driving motor on extremely insulating reliability is difficult to meet, on the other hand, the three-dimensional skeleton belongs to a highly rigid static network structure, the heat expansion coefficient of the three-dimensional skeleton is seriously mismatched with that of a semiconductor chip, and the material lacks a stress self-discipline mechanism, when the material is subjected to frequent thermal shock circulation, huge heat stress accumulated at an interface cannot be effectively released, the package is extremely easy to generate micro-nano hole expansion even macroscopic interface debonding, and the structural integrity of the device cannot be ensured under the extreme temperature difference. In view of the foregoing, a need exists for a novel epoxy packaging composite material that can achieve high thermal conductivity and low expansion on the underlying molecular skeleton, and that can achieve local thermal stress self-adaptive cancellation without sacrificing insulating dielectric properties and without macroscopic creep. Disclosure of Invention The invention aims to solve the industrial problems that the thermal expansion mismatch of the existing high-heat-conductivity packaging system is easy to crack, and the conventional dynamic covalent bond material is introduced to cause free catalyst to cause breakdown and leakage. The specific technical scheme is as follows: The epoxy resin composite material is prepared from the following raw materials, by weight, 60-100 parts of a four-aromatic-ring rigid liquid crystal oriented epoxy resin, 35-55 parts of a curing agent, 0.1-0.5 part of a curing accelerator, 3-5 parts of an immobilized catalyst auxiliary agent and 300-400 parts of a heat conducting filler, wherein the immobilized catalyst auxiliary agent is FDU12-g-TBD, and consists of FDU-12 mesoporous silica and 1,5, 7-triazabicyclo [4.4.0] dec-5-ene groups covalently bonded to the surface of the FDU-12 mesoporous silica, and the four-aromatic-ring rigid liquid crystal oriented epoxy resin has a molecular structure that: 。 The preparation method of the four-aromatic-ring rigid liquid crystal oriented epoxy resin comprises the steps of taking 4,4' -biphenol, adding a tetrahydrofuran solvent of triethylamine, cooling to 0 ℃, then dropwise adding a tetrahydrofuran solution of parahydroxybenzoyl chloride, heating to room temperature for reaction for 12 hours after the dropwise adding is finished, precipitating reaction liquid by ice water, filtering, washing by water and recrys