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

Abstract

The invention discloses a high-frequency copper-clad plate with high peel strength and a preparation method thereof, and particularly belongs to the field of manufacturing of high-frequency copper-clad plates. The copper-clad plate is prepared by dipping a reinforcing material in a glue solution and then laminating and cladding copper; the glue solution is prepared from the following components in parts by mass: 20 to 40 parts of polyphenyl ether resin, 40 to 50 parts of fluorine-containing phenolic resin, 20 to 35 parts of bisphenol A cyanate resin, 40 to 55 parts of modified filler, 12 to 14 parts of curing agent, 2.5 to 4 parts of curing accelerator and 50 to 100 parts of diluent; through synergistic modification of the composite filler, polarity regulation and control of the fluorine-containing resin and optimization of process parameters, the peel strength, the dielectric property, the mechanical strength and the flame retardance of the high-frequency copper-clad plate are comprehensively improved, and the high-frequency copper-clad plate can be widely applied to the field of high-frequency electronic devices.

Description

Technical Field

[0001] The present invention belongs to the field of manufacturing high-frequency copper clad laminates, and particularly relates to a high-frequency copper clad laminate with high peel strength and a preparation method thereof. Background Art

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

[0003] The peel strength and flexural strength of traditional high-frequency copper clad laminates often fail to meet the stringent requirements of high-frequency electronic devices in complex working environments. Insufficient peel strength may cause copper foil peeling during the processing or use of the copper clad laminate, seriously affecting the reliability and stability of the device; while insufficient flexural strength will affect the overall mechanical strength and service life of the device, restricting its application in some high-stress environments.

[0004] In summary, the high-frequency copper clad laminates in the prior art still have deficiencies in terms of peel strength, heat resistance, dielectric properties, and mechanical properties, and cannot meet the high-performance requirements of modern electronic devices for high-frequency copper clad laminates. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a high-frequency copper clad laminate with high peel strength and a preparation method thereof. By adopting specific composite resin blending modification and combining the use of composite modified fillers, the present invention prepares a high-frequency copper clad laminate with high peel strength, excellent flexural strength, low dielectric constant and dielectric loss, and good flame retardancy, which can better meet the high-performance requirements of the high-frequency electronic device field.

[0006] To achieve the above purpose, the present invention discloses the following technical solutions:

[0007] In the first aspect, the present invention provides a high-frequency copper clad laminate with high peel strength, which is obtained by laminating copper on an impregnated reinforcing material with a sizing agent;

[0008] By mass, the sizing agent includes the following components:

[0009]

[0010]

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

[0012] 1-1. After uniformly mixing aramid fiber powder and spherical silica powder with a mass ratio of (2-3):1, soak them in a sodium hydroxide solution with a concentration of 30-50 wt% for 1 h-2 h, and the material-liquid ratio is 1:(5-10) g / mL.

[0013] After soaking, take them out and drain to obtain the pretreated mixed powder.

[0014] 1-2. Mix the pretreated mixed powder and 75 v / v% ethanol aqueous solution according to a material-liquid ratio of 1:(10-15) g / mL to obtain a reaction system. Stir the reaction system at (200-300) r / min for 1 h-2 h under a nitrogen atmosphere at 28°C-30°C.

[0015] 1-3. Add a certain amount of silane coupling agent to the reaction system, maintain the nitrogen atmosphere and the same stirring rate, and continue to react for 1-1.5 h, where the addition amount of the 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°C, keep the stirring rate and continue to react for 1-2 h to obtain a reaction product. Cool the reaction product to room temperature, centrifuge to obtain a precipitate, and dry the precipitate at 55-65°C for 2.5-3.5 h to obtain the modified filler.

[0017] Preferably, the preparation method of the fluorinated phenolic resin includes the following steps:

[0018] Step 2-1. Take a certain amount of formaldehyde solution with a concentration of 37 wt% and place it in a reaction vessel. Add sodium hydroxide solution with a concentration of 50% and stir evenly.

[0019] Step 2-2. Heat the reaction vessel to 50-60°C at a stirring speed of 100 r / min, and dropwise add 3-fluorophenol thereto, and complete the dropping within 40-50 min.

[0020] Step 2-3. Raise the temperature to 70-80°C and react for 2-3 h. After the reaction is completed, add an aqueous hydrochloric acid solution with a concentration of 10% to the system to adjust the pH to 6-7, and dehydrate at 60-70°C and a vacuum degree of -0.08 to -0.1 MPa for 1-2 h to obtain the fluorinated phenolic resin.

[0021] Among them, 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 alkanolamine, 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 anilinomethyltriethoxysilane and 3-ureidopropyltriethoxysilane in a mass ratio of 1:(6-8).

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

[0026] The particle size of the spherical silica powder is 5-10 μm.

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

[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 the adhesive solution: First, dissolve the polyphenylene ether resin, fluorinated phenolic resin, and bisphenol A cyanate resin with a diluent to obtain a composite resin solution. Then, mix the curing agent and the curing accelerator and add them to the composite resin solution, and stir at 2000-3000 r / min for 30-60 min. Finally, add the modified filler and continue to stir at 10000-15000 r / min for 10-30 min to obtain the adhesive solution after high-speed shear dispersion;

[0030] 3-2. Impregnation and drying: Immerse the reinforcing material in the adhesive solution, and after impregnation, dry it at 100-150 °C for 5-15 min to obtain a prepreg;

[0031] 3-3. Laminating and molding: Stack the prepreg and the copper foil, and hot press at 180-220 °C and a pressure of 10-20 MPa for 35-50 min 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 laminating and molding is as follows: First, pre-press at 180 °C for 5-10 min, and then raise the temperature to 200-220 °C for main pressing for 30-40 min.

[0034] Advantages of the present invention:

[0035] 1. The present 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 a high crosslinking density, endowing the material with relatively excellent mechanical strength and mechanical properties;

[0036] 2. The present invention introduces a composite silane coupling agent to perform surface treatment on the composite filler aramid fiber powder and spherical silicon powder, thereby significantly enhancing the interface bonding force between the filler and the resin matrix;

[0037] 3. The present invention introduces fluorine-containing phenolic resin, utilizes its low polarity characteristics, and combines the uniform dispersion of modified fillers to jointly reduce the polarity of the material, thereby achieving low loss of high-frequency signal transmission;

[0038] 4. The present invention achieves a comprehensive improvement in peel strength, dielectric properties, mechanical strength and flame retardancy of high-frequency copper clad laminates through synergistic modification of composite fillers, polarity regulation of fluorine-containing resins and optimization of process parameters, and can be widely used in the field of high-frequency electronic devices. DETAILED DESCRIPTION

[0039] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

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

[0041] In the present invention:

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

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

[0044] Aramid fiber powder: the specification is 40-80 μm in long diameter and 7-10 μm in short diameter, purchased from Zhejiang Xuantai New Materials Co., Ltd.;

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

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

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

[0048] The remaining raw materials are commercially available.

[0049] Preparation of modified fillers

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

[0051] 1-2. Mix the pretreated mixed powder and 75 v / v% ethanol aqueous solution according to a solid-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 h under a nitrogen atmosphere at 28-30 °C;

[0052] 1-3. Add a certain amount of silane coupling agent to the reaction system. First, add aniline methyltriethoxysilane coupling agent, stir evenly, and then add 3-ureidopropyltriethoxysilane coupling agent. Maintain the nitrogen atmosphere and the same stirring rate in step 1-2, and continue to react for 1-1.5 h. The mass ratio of aniline methyltriethoxysilane to 3-ureidopropyltriethoxysilane is 1:(6-8), and the addition amount of the silane coupling agent is 5-7% of the total mass of the reaction system;

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

[0054] The specific parameters are shown in Table 1.

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

[0056]

[0057] Preparation of fluorinated phenolic resin

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

[0059] 2-2. Heat the reaction vessel to 60 °C at a stirring speed of 100 r / min, and dropwise add 3-fluorophenol into it. The dropping is completed within 50 min;

[0060] 2-3. Raise the temperature to 80 °C and react for 3 h. After the reaction is completed, add 10% hydrochloric acid aqueous solution to the system to adjust the pH to 6.5, and dehydrate at 70 °C and a vacuum of -0.1 MPa for 2 h to obtain fluorinated phenolic resin;

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

[0062] Preparation of Examples

[0063] Accurately weigh according to the parts by mass of the raw materials in Table 2;

[0064] 3-1. Preparation of adhesive solution: First, dissolve polyphenylene ether resin, fluorinated phenolic resin, and bisphenol A cyanate ester resin with a diluent to obtain a composite resin solution. Then, mix the curing agent and curing accelerator and add them to the composite resin solution, and stir at 2000 - 3000 r / min for 30 - 60 min. Finally, add modifier filler 2 and continue to stir 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: Immerse the ceramic fiber cloth in the adhesive solution, and after impregnation, dry it at 100 - 150 °C for 5 - 15 min to obtain a semi-cured sheet;

[0066] 3-3. Laminating and molding: Stack the semi-cured sheets and copper foils, pre-press at 10 - 20 MPa and 180 °C for 5 - 10 min, then raise the temperature to 200 - 220 °C for main pressing for 30 - 40 min to obtain Examples 1-4 of the copper clad laminate.

[0067] Table 2 Parts by mass of raw materials and preparation parameters

[0068]

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

[0070] To verify the comprehensive performance of Examples 1-4 provided by the present invention and at the same time verify the influence of the components in the adhesive solution on the performance of the copper clad laminate, replacements or omissions are made based on the formulation of Example 3, specifically referring to the following settings:

[0071] Modifier filler 4: Surface silanization treatment is carried out using aramid fiber powder alone, that is, step 1-1 in the preparation method of modifier filler 2 is adjusted to use aramid fiber powder alone, and the remaining steps remain unchanged to obtain modifier filler 4;

[0072] Modifier filler 5: Surface silanization treatment is carried out using spherical silica powder alone, that is, step 1-1 in the preparation method of modifier filler 2 is adjusted to use spherical silica powder alone, and the remaining steps remain unchanged to obtain modifier filler 5;

[0073] Modifier filler 6: Surface silanization treatment is carried out using aniline methyltriethoxysilane alone, that is, step 1-3 in the preparation method of modifier filler 2 is adjusted to use aniline methyltriethoxysilane alone, and the remaining steps remain unchanged to obtain modifier filler 6;

[0074] Modified filler 7: The surface is silanized with 3-ureidopropyltriethoxysilane alone, that is, steps 1-3 are adjusted to use 3-ureidopropyltriethoxysilane alone on the basis of the preparation method of modified filler 2, and the remaining steps remain unchanged, obtaining modified filler 7;

[0075] Modified filler 8: On the basis of the preparation method of modified filler 2, the mass ratio of anilinomethyltriethoxysilane to 3-ureidopropyltriethoxysilane in steps 1-3 is adjusted to 1:1, and the remaining steps remain unchanged, obtaining modified filler 8;

[0076] Preparation of comparative examples

[0077] According to the preparation method of Example 3, the raw materials are accurately weighed according to Table 3. See Table 3 for details:

[0078] Table 3 Mass parts of raw materials and preparation parameters of comparative examples

[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 testing;

[0084] The test items are as follows:

[0085] Flexural 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 IPC-TM-650 2018 test standard;

[0088] Dielectric constant and dielectric loss: Tested according to the ASTM D150 specification;

[0089] Flammability: Determined by the UL-94 combustion method;

[0090] The obtained 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 Dissipation Factor (Df, 1 GHz) 0.0062 0.0052 0.0059 0.0067 0.0142 0.0093 0.0086 0.0086 0.0092 0.0079 Flammability Resistance (UL-94) V0 Rating V0 Rating V0 Rating V0 Rating V1 Rating V0 Rating V0 Rating V0 Rating V0 Rating V0 Rating

[0093] Result analysis:

[0094] According to the results in Table 4, Examples 1-4 perform excellently. Among them, the flexural strength and peel strength of Example 3 reach 644 MPa and 1.844 N / mm respectively, and the dielectric constant and dielectric loss reach 2.53 and 0.0059 respectively, with excellent dielectric properties, meeting the use requirements of high-frequency copper clad laminates. In Comparative Example 1, the lack of fluorinated phenolic resin leads to a significant decrease in flexural strength and peel strength, and at the same time, the flame retardant performance and dielectric properties also decrease, proving that the balanced ratio among polyphenylene ether resin, fluorinated phenolic resin and bisphenol A cyanate resin in the blend-modified composite resin system provided by the present invention enhances the crosslinking density and rigidity of the resin system, effectively enhancing the mechanical properties and mechanical strength of the resin. By introducing fluorinated resin, the present invention effectively reduces the dielectric constant and dielectric loss and improves the flame retardant performance.

[0095] The fillers used in Comparative Example 2 and Comparative Example 3 are separately silanized aramid fiber powder and separately silanized silica powder, resulting in a significant decrease in the flexural strength and peel strength of the adhesive solution, proving that the composite modified fillers aramid fiber powder and silica powder provided by the present invention can play a synergistic effect in the resin system. The aramid fiber powder forms a three-dimensional fiber network structure in the resin system, improving the bending resistance of the copper clad laminate through mechanical interlocking and stress transfer. The spherical silica powder, as a rigid filler, is embedded in the fiber network and restricts the plastic deformation of the resin matrix through the "pinning effect", significantly improving the rigidity and flexural strength of the material. The two cooperate with each other to effectively improve the mechanical properties and mechanical strength of the adhesive solution.

[0096] The fillers used in Comparative Example 4 and Comparative Example 5 are a certain silane coupling agent used alone, which also leads to a decrease in the peel strength and flexural strength of the material, proving that the composite silane coupling agent provided by the present invention can effectively provide the interfacial binding force and dispersion degree of inorganic fillers in the resin system when used in combination, significantly improving the mechanical properties and mechanical performance of the material, and at the same time having a beneficial effect on the dielectric properties of the material. However, the single coupling agent leads to a decrease in the interfacial binding force due to insufficient coupling efficiency, resulting in a decrease in the comprehensive performance of the material.

[0097] The peel strength and flexural strength of Comparative Example 6 are still lower than those of Example 3, indicating that the mass ratio between anilinomethyltriethoxysilane and 3-ureidopropyltriethoxysilane is one of the key factors for optimizing the coupling effect, and can also enhance the comprehensive performance of the material.

[0098] Finally, it should be noted that the above are only the 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 recorded in the foregoing embodiments or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A high-frequency copper clad laminate with high peel strength, characterized in that, The copper clad laminate is prepared by impregnating a reinforcing material with a sizing solution and then laminating and copper-cladding; By mass, the sizing solution comprises the following components: The preparation method of the modified filler comprises the following steps: 1-1. Mix aramid fiber powder and spherical silica powder with a mass ratio of (2-3):1 evenly, then soak them in a sodium hydroxide solution with a concentration of 30-50 wt% for 1 h-2 h, with a material-liquid ratio of 1:(5-10) g / mL. After soaking, take them out and drain, to obtain the pretreated mixed powder; 1-2. Mix the pretreated mixed powder and 75 v / v% ethanol aqueous solution according to a material-liquid ratio of 1:(10-15) g / mL to obtain a reaction system. Stir and react the reaction system in a nitrogen atmosphere at 28 °C-30 °C at (200-300) r / min for 1 h-2 h; 1-3. Add a certain amount of silane coupling agent to the reaction system, maintain the nitrogen atmosphere and the same stirring rate, and continue to react for 1-1.5 h, wherein the addition amount of the silane coupling agent is 5-7% of the total mass of the reaction system; 1-4. After heating the reaction system to 90-100 °C, keep the stirring rate and continue to react for 1-2 h to obtain a reaction product. Cool the reaction product to room temperature, centrifuge to obtain a precipitate, and dry the precipitate at 55-65 °C for 2.5-3.5 h to obtain the modified filler.

2. The copper clad laminate according to claim 1, wherein, The preparation method of the fluorinated phenolic resin comprises the following steps: Step 2-1. Take a certain amount of formaldehyde solution with a concentration of 37 wt% and place it in a reaction vessel, add sodium hydroxide solution with a concentration of 50%, and stir evenly; Step 2-2. Heat the reaction vessel to 50-60 °C at a stirring speed of 100 r / min, and dropwise add 3-fluorophenol thereto, and complete the dropping within 40-50 min; Step 2-3. Raise the temperature to 70-80 °C and react for 2-3 h. After the reaction is completed, add an aqueous hydrochloric acid solution with a concentration of 10% to the system to adjust the pH to 6-7, and dehydrate at 60-70 °C and a vacuum degree of -0.08--0.1 MPa for 1-2 h to obtain the fluorinated phenolic resin; Among them, the molar ratio of 3-fluorophenol, formaldehyde and sodium hydroxide is 1:(0.85-1.1):(0.01-0.03).

3. The copper clad laminate according to claim 1, characterized in that, The curing agent is at least one of alkyl alkanolamine, dicyandiamide, and triethanolamine.

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

5. The copper clad laminate according to claim 1, wherein, The silane coupling agent is composed of aniline methyltriethoxysilane and 3-ureidopropyltriethoxysilane according to a mass ratio of 1:(6-8).

6. The copper clad laminate according to claim 1, wherein The aspect ratio of the aramid fiber powder is 40-80 μm, and the short diameter is 7-10 μm; The particle size of the spherical silica powder is 5-10 μm.

7. The copper clad laminate according to claim 1, wherein The diluent is at least one of N-methyl-2-pyrrolidone, acetone, and methyl ethyl ketone.

8. The method for preparing the copper clad laminate according to any one of claims 1 to 7, characterized in that, Comprises the following steps: 3-1. Preparation of adhesive solution: First, dissolve polyphenylene ether resin, fluorinated phenolic resin, and bisphenol A cyanate ester resin with a diluent to obtain a composite resin solution. Then, mix the curing agent and curing accelerator and add them to the composite resin solution, and stir at 2000 - 3000 r / min for 30 - 60 min. Finally, add the modified filler and continue to stir at 10000 - 15000 r / min for 10 - 30 min. After high-speed shear dispersion, the adhesive solution is obtained; 3-2. Impregnation and drying: Immerse the reinforcing material in the adhesive solution, and after impregnation, dry it at 100 - 150 °C for 5 - 15 min to obtain a prepreg; 3-3. Laminating and molding: Stack the prepreg and copper foil, and hot press at 180 - 220 °C and a pressure of 10 - 20 MPa for 35 - 50 min to obtain the copper clad laminate.

9. The preparation method according to claim 8, characterized in that, The reinforcing material is at least one of glass fiber cloth and ceramic fiber cloth.

10. The preparation method according to claim 8, characterized in that, The hot pressing in the laminating and molding is as follows: First, pre-press at 180 °C for 5 - 10 min, and then raise the temperature to 200 - 220 °C for main pressing for 30 - 40 min.

Images