Preparation method of polyphenyl ether composite medium copper-clad plate
By mixing in a supercritical CO2 environment and using electrospinning technology and vertical strong magnetic field hot pressing curing, the problems of nanofiller agglomeration and low thermal conductivity efficiency were solved, achieving high performance and high reliability of polyphenylene ether composite dielectric copper clad laminate.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-26
- Publication Date
- 2026-03-27
AI Technical Summary
Existing technologies cannot completely overcome the agglomeration of nanofillers in viscous resin solutions, which leads to damage to the mechanical properties of materials and increased dielectric loss. At the same time, the heat conduction network efficiency of traditional preparation methods is low, and it is not possible to effectively dissipate the heat of high-power electronic devices.
Pure polyphenylene ether resin, surface modifier and boron nitride nanosheets were mixed in a supercritical CO2 environment and electrospun to form a silica nanofiber network. The network was then hot-pressed and cured under a vertical strong magnetic field to achieve uniform dispersion and directional arrangement of the filler.
This achieves uniform dispersion of fillers at the molecular level, improving the mechanical and dielectric properties of the material. At the same time, it forms an efficient vertical heat conduction path, reducing the chip junction temperature and improving the reliability of electronic devices.
Smart Images
Figure SMS_1
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of polyphenyl ether composite dielectric copper-clad plate production, and particularly relates to a preparation method of a polyphenyl ether composite dielectric copper-clad plate. BACKGROUND
[0002] Polyphenyl ether (PPO or PPE) resin is considered as an ideal dielectric material for preparing copper-clad plates for high-frequency and high-speed communication due to its inherent low dielectric constant (Dk) and extremely low dielectric loss factor (Df). However, pure PPO resin has problems such as poor solvent resistance, weak adhesion and easy creep at high temperature, and therefore, in actual industrial production, it must be modified and prepared into a composite dielectric material.
[0003] At present, the mainstream polyphenyl ether composite dielectric copper-clad plate preparation technology in the industry generally follows the following path: first, the PPO resin is chemically modified or blended with other resins to improve its cross-linking ability and process adaptability; then, the modified resin is dissolved in a solvent and physically blended with inorganic fillers such as silicon dioxide and aluminum hydroxide by mechanical stirring to form a glue solution; then, the reinforcing material, usually electronic-grade glass fiber cloth, is impregnated with the glue solution and heated in an oven to make a prepreg; finally, multiple layers of prepregs and copper foils are laminated, and curing is completed by heating and pressing in a hot press to obtain the final copper-clad plate product.
[0004] In the prior art, high-shear mechanical stirring is generally used for filler dispersion. This method is difficult to completely overcome the van der Waals force of nanofillers, which leads to their easy re-agglomeration in the viscous resin glue solution. These agglomerates will become stress concentration points in the subsequent lamination process, not only damaging the mechanical properties of the material, but also causing local field distortion under high-frequency electric field, increasing dielectric loss.
[0005] Secondly, the traditional preparation method randomly disperses the heat-conducting fillers (such as boron nitride and aluminum oxide) in the resin matrix, forming an isotropic heat conduction network, which is low in efficiency for the application of copper-clad plates whose main heat dissipation direction is the thickness direction (vertical direction). The heat generated during device operation cannot be efficiently conducted vertically through the plate to the heat sink, resulting in high chip junction temperature and seriously restricting the reliability of high-power and high-integration electronic devices.
[0006] In view of this, the present application provides a preparation method of a polyphenyl ether composite dielectric copper-clad plate to solve the above problems. SUMMARY
[0007] To achieve the above-mentioned purpose, the present application provides the following technical scheme: a preparation method of a polyphenyl ether composite dielectric copper-clad plate, comprising the following steps:
[0008] S1: mixing pure polyphenyl ether resin powder, phthalonitrile-terminated PPO oligomer containing surface modifier, and suspension of amino-functionalized boron nitride nanosheet in a supercritical CO2 environment to obtain an activated, premixed filler-containing PPO composite resin matrix;
[0009] S2: dissolving the PPO composite resin matrix into a PPO glue solution, using electrospinning technology to spin a precursor solution of tetraethyl orthosilicate into the PPO glue solution to form a silica nanofiber network in situ;
[0010] S3: coating the PPO glue solution containing fillers on a copper foil treated by plasma, and obtaining a flat plate by heat pressing and curing.
[0011] As a preferred preparation method of the polyphenyl ether composite medium copper-clad plate, the heat pressing and curing in S3 is performed under a vertical strong magnetic field with stepwise temperature rising.
[0012] As a preferred preparation method of the polyphenyl ether composite medium copper-clad plate, the temperature of the supercritical CO2 environment in S1 is 50-70℃, and the pressure is 10-20 MPa; the mixing condition is mixing for 10-60 minutes at a rotation speed of 500 rpm.
[0013] As a preferred preparation method of the polyphenyl ether composite medium copper-clad plate, the heat pressing and curing with stepwise temperature rising in S3 includes the following three stages:
[0014] First stage: slowly rising from 80℃ to 150℃ under a pressure of 0.3-0.8 MPa and a vertical strong magnetic field;
[0015] Second stage: rising to 160-200℃, and increasing the pressure to 1.0-2.0 MPa for intermediate curing;
[0016] Third stage: continuously rising to 210-240℃, and maintaining the pressure for post-curing.
[0017] As a preferred preparation method of the polyphenyl ether composite medium copper-clad plate, the plasma treatment in S3 is helium-oxygen plasma treatment on the copper foil.
[0018] As a preferred preparation method of the polyphenyl ether composite medium copper-clad plate, the helium-oxygen plasma treatment is performed with a gas flow ratio of He:O2 of 90:10-97:3.
[0019] As a preferred preparation method of the polyphenyl ether composite medium copper-clad plate, in the helium-oxygen plasma treatment, the radio frequency power of the plasma spray gun is 500 W, and the treatment distance between the spray gun nozzle and the surface of the copper foil is accurately 5 mm.
[0020] Compared with the prior art, the present application has the beneficial effects that:
[0021] 1. The present application utilizes the high permeability and zero surface tension characteristics of supercritical CO2, achieving uniform dispersion at the molecular level, and the functional groups on the surface of the filler form strong interfacial bonding with the resin, thereby maintaining extremely low dielectric loss while improving the mechanical properties of the material;
[0022] 2. The present application forms a network of silica nanofibers, which can greatly inhibit the flow and shrinkage of the resin during curing, and also effectively stabilize the size and improve the tensile strength;
[0023] 3. The present application can induce the vertical orientation of boron nitride nanosheets by vertical magnetic field hot pressing and curing, forming an efficient vertical heat conduction path to reduce the junction temperature of high-power chips and improve system reliability. DETAILED DESCRIPTION
[0024] The technical solutions in the embodiments of the present application will be described below in a clear and complete manner. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.
[0025] Embodiment one:
[0026] The present application relates to a preparation method of a polyphenyl ether composite dielectric copper-clad plate, comprising:
[0027] 100 parts by weight of polyphenyl ether resin powder is placed in a supercritical reaction kettle. Liquid CO2 is introduced, the temperature is raised to 60℃, the pressure is increased to 15MPa, and this supercritical state is maintained for 30 minutes. Then, a suspension containing 15 parts by weight of phthalonitrile-terminated PPO oligomer and 8 parts by weight of amino-functionalized boron nitride nanosheets (sheet diameter 1-2μm) is injected into the kettle through a high-pressure pump. Stirring and mixing are carried out at a speed of 500rpm for 1 hour, and then slow pressure relief is performed to obtain an activated and uniformly dispersed PPO composite resin matrix;
[0028] It should be noted that supercritical CO2 has high diffusivity like a gas and high density like a liquid. It can penetrate and swell the PPO molecular chain, reduce the viscosity of the system, and create optimal conditions for uniform dispersion of subsequent components; as an active modifier and crosslinking agent, the phthalonitrile-terminated PPO oligomer will undergo addition polymerization of the terminal phthalonitrile group during subsequent hot pressing and curing, forming a high-performance phthalocyanine structure that significantly improves heat resistance and forms a crosslink with the main PPO resin; the amino-functionalized boron nitride nanosheet as a thermal and reinforcing filler, the amino group (-NH2) on its surface can react with the PPO chain or modifier to improve the interfacial bonding, and in a supercritical environment, they can achieve uniform dispersion without agglomeration; the surface modifier is usually a silane coupling agent, which is used to coat the nanofiller in advance to further improve its compatibility and dispersion stability in the resin matrix.
[0029] The above obtained resin matrix was dissolved in a mixture of toluene or butanone (weight ratio 1:1) to form a PPO glue solution, and the solid content of the PPO glue solution was controlled at 65%, which was used as the collection liquid for electrospinning. A concentration of 20wt% of tetraethyl orthosilicate was prepared, and electrospinning was carried out at a high voltage of 15kV and a propelling speed of 0.5 mL / h. The fibers were directly sprayed and collected in the lower flowing PPO glue solution, and the process was continued until a uniform three-dimensional nanofiber network was formed in the PPO glue solution.
[0030] It should be noted that the tetraethyl orthosilicate precursor forms silica nanofibers during electrospinning and subsequent hydrolysis, and this fiber network can effectively inhibit the excessive flow and shrinkage of PPO resin during the curing process, significantly improving the dimensional stability and mechanical strength, and it is also a low dielectric material itself.
[0031] The above obtained PPO glue solution was coated on a release film and dried in an oven at 130°C for 5 minutes to form a semi-cured sheet. Two copper foils with a thickness of 18μm were prepared, and the rough surface of the copper foils was treated by atmospheric helium-oxygen plasma. The treatment parameters included: RF power of the spray gun: 500W power, He:O2=95:5, treatment distance 5mm, treatment time 30 seconds. The four semi-cured sheets were then laminated. The laminated body was placed in a hot press providing a vertical magnetic field of 1.0 T. The curing process was as follows: from room temperature to 150°C at a rate of 1.5°C / min, pressure 0.5MPa for 30 minutes to orient the boron nitride nanosheet; then to 180°C at a rate of 1.0°C / min, pressure 1.5MPa for 1 hour; finally to 220°C, pressure 1.5MPa for post-curing for 2 hours.
[0032] It should be noted that slow stepwise heating allows the resin to flow, infiltrate, and gives the nanofiller enough time to complete the orientation under the magnetic field, while avoiding internal stress caused by rapid solidification; a vertical strong magnetic field can orient the originally randomly distributed sheet-shaped boron nitride in the vertical direction (i.e. the thickness direction of the laminate), thereby greatly improving the thermal conductivity of the board in the vertical direction, facilitating the conduction of heat generated by the PCB to the metal heat sink.
[0033] Comparative Example 1
[0034] The PPO / BN mixture was prepared by a conventional mechanical stirring method, the same reinforcing glass cloth was used, there was no magnetic field orientation step, the copper foil was only subjected to conventional brown processing, and the remaining steps were similar to those of Example 1. The properties of the copper-clad plate prepared were compared with those of the copper-clad plate prepared by the method of Example 1, as shown in Table 1 below.
[0035]
[0036] Table 1
[0037] Finally, it should be noted that the above only describes the preferred embodiments of the present application and is not intended to limit the present application. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent replacements to some technical features. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application shall be included in the protection scope of the present application.
Claims
1. A method for preparing a polyphenylene ether composite copper clad plate, characterized in that, The method comprises the following steps: S1: mixing pure polyphenylene ether resin powder, phthalonitrile-terminated PPO oligomer containing a surface modifier, and a suspension of amino-functionalized boron nitride nanosheets in a supercritical CO2 environment to obtain an activated, premixed filler-filled PPO composite resin matrix; S2: dissolving the PPO composite resin matrix into a PPO glue solution, using an electrospinning technique to spin a precursor solution of tetraethyl orthosilicate into the PPO glue solution, and in-situ forming a silica nanofiber network; S3: coating the PPO glue solution containing the fillers on a copper foil subjected to plasma treatment, and obtaining a flat plate through heat pressing and curing.
2. The method for preparing polyphenylene ether composite dielectric copper-clad laminate according to claim 1, characterized in that: The heat pressing and curing in S3 is performed in a vertical strong magnetic field through stepwise heating.
3. The method for preparing polyphenylene ether composite dielectric copper-clad laminate according to claim 1, characterized in that: The temperature of the supercritical CO2 environment in S1 is 50-70°C, and the pressure is 10-20 MPa; the mixing condition is mixing for 10-60 minutes at a rotation speed of 500 rpm.
4. The method for preparing polyphenylene ether composite dielectric copper-clad laminate according to claim 2, characterized in that: The heat pressing and curing through stepwise heating in S3 comprises the following three stages: First stage: slowly heating from 80°C to 150°C under a pressure of 0.3-0.8 MPa and a vertical strong magnetic field; Second stage: heating to 160-200°C, and increasing the pressure to 1.0-2.0 MPa for intermediate curing; Third stage: continuously heating to 210-240°C, and maintaining the pressure for post-curing.
5. The method for preparing polyphenylene ether composite dielectric copper-clad laminate according to claim 1, characterized in that: The plasma treatment in S3 is helium-oxygen plasma treatment on the copper foil.
6. The method for preparing polyphenylene ether composite dielectric copper-clad laminate according to claim 5, characterized in that: In the helium-oxygen plasma treatment, the gas flow ratio He:O2 is 90:10-97:
3.
7. The method for preparing polyphenylene ether composite dielectric copper-clad laminate according to claim 5, characterized in that: In the helium-oxygen plasma treatment, the radio frequency power of the plasma spray gun is 300-800 W, and the treatment distance between the spray gun nozzle and the surface of the copper foil is accurately 2-5 mm.