High-frequency copper-clad plate with high peel strength and preparation method thereof

Abstract

The application discloses a high-frequency copper-clad plate with high peeling strength and a preparation method thereof, and belongs to the field of high-frequency copper-clad plate manufacturing. The copper-clad plate is prepared by laminating copper after impregnating a glue solution into a reinforcing material. The glue solution comprises the following components in mass fractions: 20-40 parts of polyphenyl ether resin, 40-50 parts of fluorine-containing phenolic resin, 20-35 parts of bisphenol A cyanate ester resin, 40-55 parts of modified filler, 12-14 parts of curing agent, 2.5-4 parts of curing accelerator and 50-100 parts of diluent. The application realizes comprehensive improvement of the high-frequency copper-clad plate in peeling strength, dielectric property, mechanical strength and flame retardancy through synergistic modification of composite fillers, polarity regulation of fluorine-containing resin and process parameter optimization, and can be widely applied in the field of high-frequency electronic devices.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of high-frequency copper-clad plate manufacturing, and particularly relates to a high-frequency copper-clad plate with high peeling strength and a preparation method thereof. BACKGROUND

[0002] As a key basic material in modern electronic information technology, high-frequency copper-clad plate is widely used in high-frequency electronic device fields such as high-speed communication, aerospace, automotive electronics, medical equipment and 5G base station. With the rapid development of technologies in these fields, the performance requirements of high-frequency copper-clad plate are also increasing, especially in terms of peeling strength, bending strength, dielectric performance and flame retardancy. However, the high-frequency copper-clad plate in the prior art still faces many challenges in meeting these high-performance requirements.

[0003] The peeling strength and bending strength of traditional high-frequency copper-clad plate often cannot meet the stringent requirements of high-frequency electronic devices in complex working environments. Insufficient peeling strength may cause copper foil to fall off during processing or use, seriously affecting the reliability and stability of the device; and insufficient bending strength will affect the overall mechanical strength and service life of the device, limiting its application in certain high-stress environments.

[0004] In summary, the high-frequency copper-clad plate in the prior art still has deficiencies in peeling strength, heat resistance, dielectric performance and mechanical properties, and cannot meet the high-performance requirements of modern electronic devices for high-frequency copper-clad plate. SUMMARY

[0005] In view of the deficiencies of the prior art, the present application aims to provide a high-frequency copper-clad plate with high peeling strength and a preparation method thereof. The present application prepares a high-frequency copper-clad plate with high peeling strength, excellent bending strength, low dielectric constant and dielectric loss, and good flame retardancy by using specific composite resin blending modification and combining the use of composite modified fillers, which can better meet the high-performance requirements of the high-frequency electronic device field.

[0006] To achieve the above-mentioned purpose, the present application discloses the following technical solutions:

[0007] In a first aspect, the present application provides a high-frequency copper-clad plate with high peeling strength, which is prepared by laminating copper cladding after impregnating a reinforcing material with a glue solution.

[0008] The glue solution includes the following components by mass fraction:

[0009]

[0010]

[0011] The preparation method of the modified filler includes the following steps:

[0012] 1-1. Mix aramid fiber powder and spherical silicon powder in a mass ratio of (2-3):1, then immerse them in a 30-50wt% sodium hydroxide solution for 1-2h, with a solid-liquid ratio of 1:(5-10)g / mL,

[0013] After soaking, drain and obtain the pretreated mixed powder;

[0014] 1-2. Mix the pretreated mixed powder with 75v / v% ethanol solution at a solid-liquid ratio of 1:(10-15)g / mL to obtain a reaction system, and stir the reaction system at (200-300)r / min under a nitrogen atmosphere at 28-30℃ for 1-2h;

[0015] 1-3. Add a certain amount of silane coupling agent to the reaction system, maintain the nitrogen atmosphere and the same stirring speed, and continue to react for 1-1.5h, wherein the addition amount of silane coupling agent is 5-7% of the total mass of the reaction system;

[0016] 1-4. After heating the reaction system to 90-100℃, keep the stirring speed and continue to react for 1-2h to obtain a reaction product, cool the reaction product to room temperature, centrifugal separation to obtain a precipitate, and dry the precipitate at 55-65℃ for 2.5-3.5h to obtain the modified filler.

[0017] Preferably, the preparation method of the fluorine-containing phenolic resin comprises the following steps:

[0018] Step 2-1. Put a certain amount of 37wt% formaldehyde solution into a reaction container, add 50% sodium hydroxide solution, and stir uniformly;

[0019] Step 2-2. Heat the reaction container to 50-60℃ at a stirring speed of 100r / min, and add 3-fluorophenol dropwise into the container, which is completed within 40-50min;

[0020] Step 2-3. Increase the temperature to 70-80℃, react for 2-3h, then add 10% hydrochloric acid solution into the system to adjust the pH to 6-7, and dehydrate at 60-70℃ under a vacuum degree of-0.08 to-0.1MPa for 1-2h to obtain the fluorine-containing phenolic resin;

[0021] Wherein, the molar ratio of 3-fluorophenol, formaldehyde and sodium hydroxide is 1:(0.85-1.1):(0.01-0.03).

[0022] Preferably, the curing agent is at least one of alkyl alcohol amine, dicyandiamide and triethanolamine.

[0023] Preferably, the curing accelerator is at least one of 2-methylimidazole and 2-ethyl-4-methylimidazole.

[0024] Preferably, the silane coupling agent is composed of aniline methyltriethoxysilane and 3-ureapropyltriethoxysilane in a mass ratio of 1:(6-8).

[0025] Preferably, the aramid fiber powder has a major diameter of 40-80 μm and a minor diameter of 7-10 μm;

[0026] The spherical silica powder has a particle size of 5-10 μm.

[0027] Preferably, the diluent is at least one of N-methyl-2-pyrrolidone, acetone, and butanone.

[0028] In a second aspect, the present invention provides a method for preparing the copper-clad laminate described in the first aspect, comprising the following steps:

[0029] 3-1. Preparation of adhesive solution: First, dissolve polyphenylene ether resin, fluorinated phenolic resin and bisphenol A cyanate resin in a diluent to obtain a composite resin solution. Then, mix the curing agent and curing accelerator and add them to the composite resin solution. Stir at 2000-3000 r / min for 30-60 min. Finally, add the modified filler and continue stirring at 10000-15000 r / min for 10-30 min. After high-speed shear dispersion, the adhesive solution is obtained.

[0030] 3-2. Impregnation and drying: Impregnate the reinforcing material in the adhesive solution, and after impregnation, dry it at 100-150℃ for 5-15 minutes to obtain a semi-cured sheet;

[0031] 3-3. Lamination molding: The prepreg and copper foil are laminated and hot-pressed at 180-220℃ and 10-20MPa for 35-50 minutes to obtain the copper-clad laminate.

[0032] Preferably, the reinforcing material is at least one of glass fiber cloth and ceramic fiber cloth.

[0033] Preferably, the hot pressing in the lamination process is as follows: first, pre-press at 180°C for 5-10 minutes, and then heat to 200-220°C for main pressing for 30-40 minutes.

[0034] The beneficial effects of this invention are:

[0035] 1. This invention utilizes the three-dimensional network structure of aramid fibers and the rigid filling of spherical silica powder to form a composite reinforcement system, combined with a resin matrix with high cross-linking density, to endow the material with superior mechanical strength and mechanical properties.

[0036] 2. This invention significantly enhances the interfacial bonding force between the filler and the resin matrix by introducing a composite silane coupling agent to perform surface treatment on the composite filler aramid fiber powder and spherical silica powder;

[0037] 3. This invention introduces fluorinated phenolic resin, utilizing its low polarity characteristics, and combines this with the uniform dispersion of modified fillers to further reduce material polarity, thereby achieving low loss in high-frequency signal transmission.

[0038] 4. This invention achieves a comprehensive improvement in peel strength, dielectric properties, mechanical strength and flame retardancy of high-frequency copper-clad laminates through synergistic modification with composite fillers, polarity control of fluorinated resins and optimization of process parameters, and can be widely used in the field of high-frequency electronic devices. Detailed Implementation

[0039] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0040] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are only used to explain the present invention and are not intended to limit the present invention.

[0041] In this invention:

[0042] Polyphenylene oxide resin: thermosetting polyphenylene oxide resin (PPE), purchased from Nagase (China) Co., Ltd.;

[0043] Bisphenol A cyanate resin: purchased from Shanghai Haohong Biomedical Technology Co., Ltd.;

[0044] Aramid fiber powder: with a major diameter of 40-80μm and a minor diameter of 7-10μm, purchased from Zhejiang Xuantai New Materials Co., Ltd.

[0045] Aniline methyltriethoxysilane: purchased from Nanjing Pinning Coupling Agent Co., Ltd.;

[0046] 3-Ureapropyltriethoxysilane: purchased from Nanjing Pinning Coupling Agent Co., Ltd.;

[0047] Spherical silica powder: particle size 5-10μm, purchased from Suzhou Qiuyi New Materials Co., Ltd.;

[0048] All other raw materials are commercially available.

[0049] Preparation of modified fillers

[0050] 1-1. Mix aramid fiber powder and spherical silica powder in a mass ratio of (2-3):1 evenly, then soak them in a 30-50 wt% sodium hydroxide solution for 1-2 hours. The material-to-liquid ratio is 1:(5-10) g / mL. After soaking, remove the mixture and drain it to obtain the pretreated mixed powder.

[0051] 1-2. The pretreated mixed powder and 75 v / v% ethanol aqueous solution are mixed at a material-to-liquid ratio of 1:(10-15) g / mL to obtain a reaction system. The reaction system is stirred at (200-300) r / min for 1-2 hours under a nitrogen atmosphere at 28-30℃.

[0052] 1-3. Add a certain amount of silane coupling agent to the reaction system. First, add aniline methyltriethoxysilane coupling agent and stir evenly. Then add 3-ureapropyltriethoxysilane coupling agent. Maintain the nitrogen atmosphere and the same stirring rate as in steps 1-2 and continue the reaction for 1-1.5 hours. The mass ratio of aniline methyltriethoxysilane to 3-ureapropyltriethoxysilane is 1:(6-8). The amount of silane coupling agent added is 5-7% of the total mass of the reaction system.

[0053] 1-4. After heating the reaction system to 90-100℃, maintain the stirring rate and continue the reaction for 1-2 hours to obtain the reaction product. Cool the reaction product to room temperature, centrifuge to obtain the precipitate, and dry the precipitate at 55-65℃ for 2.5-3.5 hours to obtain the modified filler.

[0054] See Table 1 for specific parameters.

[0055] Table 1 Raw material mass ratio and preparation parameters

[0056]

[0057] Preparation of fluorinated phenolic resins

[0058] 2-1. Take a certain amount of 37wt% formaldehyde solution and place it in a reaction vessel. Add 50% sodium hydroxide solution and stir until homogeneous.

[0059] 2-2. Heat the reaction vessel to 60°C with a stirring speed of 100 r / min, and add 3-fluorophenol dropwise over 50 min.

[0060] 2-3. Increase the temperature to 80℃ and react for 3 hours. After the reaction is complete, add a 10% hydrochloric acid aqueous solution to the system to adjust the pH to 6.5. Dehydrate at 70℃ and vacuum degree -0.1MPa for 2 hours to obtain fluorinated phenolic resin.

[0061] The molar ratio of 3-fluorophenol, formaldehyde, and sodium hydroxide is 1:0.93:0.02.

[0062] Preparation of Examples

[0063] Weigh the raw materials precisely according to the mass fractions in Table 2;

[0064] 3-1. Preparation of adhesive solution: First, dissolve polyphenylene ether resin, fluorinated phenolic resin and bisphenol A cyanate resin in a diluent to obtain a composite resin solution. Then, mix the curing agent and curing accelerator and add them to the composite resin solution. Stir at 2000-3000 r / min for 30-60 min. Finally, add modified filler 2 and continue stirring at 10000-15000 r / min for 10-30 min. After high-speed shear dispersion, the adhesive solution is obtained.

[0065] 3-2. Impregnation and drying: Impregnate the ceramic fiber cloth in the adhesive solution, and after impregnation, dry it at 100-150℃ for 5-15 minutes to obtain a semi-cured sheet;

[0066] 3-3. Lamination molding: The prepreg and copper foil are laminated, prepressed at 10-20 MPa and 180°C for 5-10 min, and then heated to 200-220°C for main pressing for 30-40 min to obtain the copper-clad laminate of Examples 1-4.

[0067] Table 2 Raw material mass fractions and preparation parameters

[0068]

[0069] Note: " / " in the table indicates no addition.

[0070] To verify the overall performance of Examples 1-4 provided by this invention, and to verify the influence of the components in the adhesive on the performance of the copper-clad laminate, substitutions or omissions were made based on the formulation of Example 3, specifically referring to the following settings:

[0071] Modified filler 4: Surface silanization treatment is performed using aramid fiber powder alone. That is, based on the preparation method of modified filler 2, step 1-1 is adjusted to use aramid fiber powder alone, while the other steps remain unchanged, to obtain modified filler 4.

[0072] Modified filler 5: Surface silanization treatment is performed using spherical silica powder alone. That is, based on the preparation method of modified filler 2, step 1-1 is adjusted to use spherical silica powder alone, while the other steps remain unchanged, to obtain modified filler 5.

[0073] Modified filler 6: Surface silanization treatment is performed using aniline methyltriethoxysilane alone. That is, based on the preparation method of modified filler 2, steps 1-3 are adjusted to use aniline methyltriethoxysilane alone, while the other steps remain unchanged, to obtain modified filler 6.

[0074] Modified filler 7: Surface silanization treatment is performed using 3-ureapropyltriethoxysilane alone. That is, based on the preparation method of modified filler 2, steps 1-3 are adjusted to use 3-ureapropyltriethoxysilane alone, while the other steps remain unchanged, to obtain modified filler 7.

[0075] Modified filler 8: Based on the preparation method of modified filler 2, the mass ratio of aniline methyltriethoxysilane to 3-ureapropyltriethoxysilane in steps 1-3 is adjusted to 1:1, while the other steps remain unchanged, to obtain modified filler 8;

[0076] Preparation of comparative examples

[0077] The preparation method of Example 3 was followed, and the raw materials were accurately weighed according to Table 3. Please refer to Table 3 for details:

[0078] Table 3 Comparative Example: Raw Material Mass Parts and Preparation Parameters

[0079]

[0080]

[0081] Note: " / " in the table indicates no addition.

[0082] Performance testing

[0083] The copper-clad laminates prepared in Examples 1-4 and Comparative Examples 1-6 were subjected to performance tests.

[0084] The test items are as follows:

[0085] Bending strength: Tested according to the IPC-TM-650 2018 test standard;

[0086] Peel strength: Tested according to the IPC-TM-650 2018 test standard;

[0087] Glass transition temperature: Tested according to the 2018 test standard of IPC-TM-650;

[0088] Dielectric constant and dielectric loss: tested according to ASTM D150 standard;

[0089] Flame retardancy: determined according to the UL-94 flammability test;

[0090] The results are shown in Table 4.

[0091] Table 4 Performance Test Results

[0092] Item\Group Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Flexural strength (MPa) 577 613 644 596 354 371 326 462 494 528 Peel strength (N / mm) 1.664 1.792 1.844 1.773 1.567 1.384 1.506 1.684 1.647 1.711 Tg (°C) 266 259 276 274 233 206 244 238 221 248 Dielectric constant (Dk, 1 GHz) 2.76 2.68 2.53 2.70 3.11 3.02. 2.99 3.04 3.08 2.81 Dielectric loss (Df, 1 GHz) 0.0062 0.0052 0.0059 0.0067 0.0142 0.0093 0.0086 0.0086 0.0092 0.0079 Flame retardancy (UL-94) V0 rank V0 rank V0 rank V0 rank V1 rank V0 rank V0 rank V0 rank V0 rank V0 rank

[0093] Results analysis:

[0094] As shown in Table 4, Examples 1-4 exhibited excellent performance. Example 3, in particular, achieved a bending strength of 644 MPa and a peel strength of 1.844 N / mm, with dielectric constant and dielectric loss of 2.53 and 0.0059, respectively, demonstrating excellent dielectric properties suitable for high-frequency copper-clad laminates. In Comparative Example 1, the absence of fluorinated phenolic resin significantly reduced bending and peel strength, along with flame retardancy and dielectric properties. This demonstrates that the balanced ratio of polyphenylene ether resin, fluorinated phenolic resin, and bisphenol A cyanate resin in the blended modified composite resin system provided by this invention enhances the crosslinking density and rigidity of the resin system, effectively improving its mechanical properties and strength. This invention, by introducing fluorinated resin, effectively reduces dielectric constant and dielectric loss, and improves flame retardancy.

[0095] Comparative Examples 2 and 3 used aramid fiber powder and silica micropowder, respectively, which were silanized separately. These results in a significant decrease in the flexural strength and peel strength of the adhesive, demonstrating that the composite modified fillers aramid fiber powder and silica micropowder provided by this invention can play a synergistic role in the resin system. The aramid fiber powder forms a three-dimensional fiber network structure in the resin system, which improves the bending resistance of the copper clad laminate through mechanical interlocking and stress transfer. Meanwhile, the spherical silica micropowder, as a rigid filler, is embedded in the fiber network and restricts the plastic deformation of the resin matrix through the "pinning effect," which significantly improves the rigidity and flexural strength of the material. The two work together to effectively improve the mechanical properties and mechanical strength of the adhesive.

[0096] Comparative Examples 4 and 5 used fillers that were single silane coupling agents, which also led to a decrease in the peel strength and flexural strength of the materials. This proves that the composite silane coupling agent provided by the present invention can effectively improve the interfacial bonding force and dispersion of inorganic fillers in the resin system when used in combination, significantly improving the mechanical properties and dielectric properties of the materials. On the other hand, the single coupling agent leads to a decrease in interfacial bonding force due to insufficient coupling efficiency, resulting in a decrease in the overall performance of the materials.

[0097] The peel strength and flexural strength of Comparative Example 6 were still lower than those of Example 3, indicating that the mass ratio between aniline methyltriethoxysilane and 3-ureapropyltriethoxysilane is one of the key factors in optimizing the coupling effect and can also enhance the overall performance of the material.

[0098] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention 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 substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-peel strength high-frequency copper-clad laminate, characterized in that, The copper-clad laminate is made by impregnating a reinforcing material with an adhesive solution and then laminating it with copper. The adhesive comprises the following components by weight: 20-40 parts of polyphenylene ether resin; 40-50 parts of fluorinated phenolic resin; 20-35 parts of bisphenol A cyanate resin; 40-55 parts of modified filler; 12-14 parts of curing agent; Curing accelerator 2.5–4 parts; 50-100 parts of diluent; The method for preparing the modified filler includes the following steps: 1-1. Mix aramid fiber powder and spherical silica powder in a mass ratio of (2-3):1 evenly, then soak them in a 30-50 wt% sodium hydroxide solution for 1-2 hours. The material-to-liquid ratio is 1:(5-10) g / mL. After soaking, remove the mixture and drain it to obtain the pretreated mixed powder. 1-2. Mix the pretreated mixed powder and 75 v / v% ethanol aqueous solution at a material-to-liquid ratio of 1:(10-15) g / mL to obtain a reaction system. Stir the reaction system at (200-300) r / min for 1-2 hours under a nitrogen atmosphere at 28-30℃. 1-3. Add a certain amount of silane coupling agent to the reaction system, maintain a nitrogen atmosphere and the same stirring rate, and continue the reaction for 1 to 1.5 hours. The amount of silane coupling agent added is 5 to 7% of the total mass of the reaction system. 1-4. After heating the reaction system to 90-100℃, maintain the stirring rate and continue the reaction for 1-2 hours to obtain the reaction product. Cool the reaction product to room temperature, centrifuge to obtain the precipitate, and dry the precipitate at 55-65℃ for 2.5-3.5 hours to obtain the modified filler. The preparation method of the fluorinated phenolic resin includes the following steps: Step 2-1. Take a certain amount of 37wt% formaldehyde solution and place it in a reaction vessel. Add 50% sodium hydroxide solution and stir until homogeneous. Step 2-2. Heat the reaction vessel to 50-60°C with a stirring speed of 100 r / min, and add 3-fluorophenol dropwise over 40-50 min. Steps 2-3. Increase the temperature to 70-80℃ and react for 2-3 hours. After the reaction is complete, add a 10% hydrochloric acid aqueous solution to the system, adjust the pH to 6-7, and dehydrate for 1-2 hours at 60-70℃ and a vacuum of -0.08 to -0.1 MPa to obtain fluorinated phenolic resin. The molar ratio of 3-fluorophenol, formaldehyde, and sodium hydroxide is 1:(0.85~1.1):(0.01~0.03). The silane coupling agent is composed of aniline methyltriethoxysilane and 3-ureapropyltriethoxysilane in a mass ratio of 1:(6-8).

2. The copper-clad laminate according to claim 1, characterized in that, The curing agent is at least one of alkylolamine, dicyandiamide, and triethanolamine.

3. The copper-clad laminate according to claim 1, characterized in that, The curing accelerator is at least one of 2-methylimidazole and 2-ethyl-4-methylimidazole.

4. The copper-clad laminate according to claim 1, characterized in that, The aramid fiber powder has a major diameter of 40-80 μm and a minor diameter of 7-10 μm; The spherical silica powder has a particle size of 5-10 μm.

5. The copper-clad laminate according to claim 1, characterized in that, The diluent is at least one of N-methyl-2-pyrrolidone, acetone, and butanone.

6. A method for preparing the copper-clad laminate according to any one of claims 1 to 5, characterized in that, Includes the following steps: 3-1. Preparation of adhesive solution: First, dissolve polyphenylene ether resin, fluorinated phenolic resin and bisphenol A cyanate resin in a diluent to obtain a composite resin solution. Then, mix the curing agent and curing accelerator and add them to the composite resin solution. Stir at 2000-3000 r / min for 30-60 min. Finally, add the modified filler and continue stirring at 10000-15000 r / min for 10-30 min. After high-speed shear dispersion, the adhesive solution is obtained. 3-2. Impregnation and drying: Impregnate the reinforcing material in the adhesive solution, and after impregnation, dry it at 100-150℃ for 5-15 minutes to obtain a semi-cured sheet; 3-3. Lamination molding: The prepreg and copper foil are laminated and hot-pressed at 180-220℃ and 10-20MPa for 35-50 minutes to obtain the copper-clad laminate.

7. The preparation method according to claim 6, characterized in that, The reinforcing material is at least one of glass fiber cloth and ceramic fiber cloth.

8. The preparation method according to claim 6, characterized in that, The hot pressing in the lamination process is as follows: first, pre-press at 180°C for 5-10 minutes, then raise the temperature to 200-220°C for main pressing for 30-40 minutes.

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