Preparation method of flexible polyphenyl ether copper-clad plate

Abstract

The invention discloses a preparation method of a flexible polyphenyl ether copper-clad plate, and relates to the technical field of copper-clad plate preparation, and the preparation method comprises the following steps: S1, preparing modified polyphenyl ether resin; s2, pretreating the base material; s3, preparing a glue solution; step S4, coating and drying; s5, composite forming is carried out; the bending radius of the product is only 6-8 mm, the product can be bent for multiple times without damage and far exceeds that of a traditional product, the use requirement of flexible electronic equipment is met, the peeling strength of the copper foil is larger than or equal to 1.6 N / mm, layering is avoided after the copper foil is placed at 150 DEG C for 1000 h, the problems that the traditional product is weak in bonding and prone to failure at high temperature are solved, the dielectric constant is kept to be 2.6-2.9, the dielectric loss is smaller than or equal to 0.004, and the defects of bubbles, pinholes and the like are overcome; and parameters in each step are controllable, raw materials are easy to obtain, special equipment is not needed, and mass production can be directly carried out by using an existing copper-clad plate production line.

Description

Technical Field

[0001] This invention relates to the field of copper clad laminate preparation technology, specifically to a method for preparing a flexible polyphenylene ether copper clad laminate. Background Technology

[0002] Copper clad laminates are the core substrate of printed circuit boards, and their performance directly determines the operational stability of electronic devices. Polyphenylene ether resin, due to its low dielectric constant, good high-temperature resistance, and high mechanical strength, has become the preferred substrate for high-frequency and high-speed copper clad laminates. However, the traditional polyphenylene ether resin molecular chain is rigid, resulting in copper clad laminates with poor flexibility and a bending radius typically greater than 30mm, which cannot meet the bending installation requirements of flexible electronic devices and wearable devices.

[0003] Existing improvement methods have significant drawbacks: adding only plasticizers leads to plasticizer migration, causing performance degradation after long-term use; replacing with ordinary flexible substrates results in insufficient peel strength between the copper foil and the substrate due to poor compatibility between the substrate and polyphenylene ether resin, making delamination prone to occur at high temperatures; single solvent and single drying processes easily cause uneven adhesive dispersion and incomplete solvent evaporation, leading to defects such as bubbles and pinholes, and increased dielectric loss. Therefore, developing a method for preparing polyphenylene ether copper-clad laminates that balances flexibility, bonding strength, high-temperature resistance, and dielectric stability has significant industrial application value. Summary of the Invention

[0004] To solve the above-mentioned technical problems, a method for preparing flexible polyphenylene ether copper-clad laminate is provided, which solves the problems existing in the background technology.

[0005] To achieve the above objectives, the technical solution adopted by this invention is: a method for preparing flexible polyphenylene ether copper-clad laminate, comprising the following steps:

[0006] Step S1, Preparation of modified polyphenylene ether resin: Mix polyphenylene ether resin and flexible modifier at a mass ratio of 80-95:5-20, melt and stir at 160-180℃ for 30-60 min, cool and then pulverize to obtain modified polyphenylene ether resin powder.

[0007] Step S2, Substrate Pretreatment: Select polyimide fiber cloth as flexible reinforcing substrate, treat it with plasma for 10-20 min, then immerse it in coupling agent solution for 20-40 min, and dry it for later use;

[0008] Step S3, preparation of adhesive solution: Mix the modified polyphenylene ether resin powder, curing agent and accelerator from step S1 at a mass ratio of 100:5-15:0.5-2, add organic solvent to adjust the solid content to 40-60%, and stir evenly to obtain composite adhesive solution;

[0009] Step S4, Coating and Drying: The composite adhesive is evenly coated on both sides of the pretreated flexible reinforced substrate, with a coating amount of 20-40 g / m². First, it is dried at 80-90℃ for 10-15 min, and then dried at 110-120℃ for 10-15 min to obtain the prepreg.

[0010] Step S5, Composite Molding: The prepreg and electrolytic copper foil are stacked in a "copper foil-prepreg-copper foil" structure and placed in a hot press. The hot press is carried out at a temperature of 200-240℃ and a pressure of 1.5-3.0MPa for 30-60 minutes. After cooling, a flexible polyphenylene ether copper-clad laminate is obtained.

[0011] Preferably, the flexible modifier in step S1 is hydroxyl-terminated polybutadiene or polyethersulfone with a molecular weight of 1000-5000.

[0012] Preferably, the coupling agent solution in step S2 is an aqueous solution of γ-aminopropyltriethoxysilane in ethanol, and the mass fraction of the coupling agent is 1-3%.

[0013] Preferably, the curing agent in step S3 is dicyandiamide or 4,4'-diaminodiphenyl sulfone; the organic solvent is a mixture of toluene and acetone in a volume ratio of 1:1 to 3:1.

[0014] Preferably, the thickness of the electrolytic copper foil in step S5 is 12-70 μm, and the surface roughness Ra is 0.3-1.0 μm.

[0015] Preferably, in step S2, the substrate drying temperature is 100-110℃ and the drying time is 20-30 min.

[0016] Compared with existing technologies, the advantages of this invention are: the product bending radius is only 6-8mm, which can achieve multiple bends without damage, far exceeding traditional products, meeting the needs of flexible electronic devices; the copper foil peel strength is ≥1.6N / mm, and there is no delamination after 1000h at 150℃, solving the problems of weak adhesion and easy failure at high temperatures in traditional products; the dielectric constant is maintained at 2.6-2.9, the dielectric loss is ≤0.004, and there are no defects such as bubbles and pinholes, which are suitable for the low-loss transmission requirements of high-frequency signals; the parameters of each step are controllable; the raw materials are readily available; no special equipment is required; and mass production can be carried out directly using existing copper clad laminate production lines. Detailed Implementation

[0017] The following description is intended to disclose the invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art.

[0018] Example 1

[0019] Step S1, Preparation of modified polyphenylene ether resin: 85g of polyphenylene ether resin and 15g of hydroxyl-terminated polybutadiene are mixed, melt-stirred at 170℃ for 45min, cooled and pulverized to obtain modified polyphenylene ether resin powder.

[0020] Step S2, Substrate Pretreatment: Polyimide fiber cloth is selected as the flexible reinforcing substrate, treated with 400W plasma for 15 min, then immersed in 2% (w / w) γ-aminopropyltriethoxysilane ethanol aqueous solution for 30 min, and dried at 100℃ for 25 min for later use.

[0021] Step S3, preparation of adhesive solution: Mix 100g of modified polyphenylene ether resin powder, 10g of dicyandiamide and 1g of accelerator 2-methylimidazole, add a mixture of toluene and acetone to adjust the solid content to 50%, and stir evenly to obtain composite adhesive solution;

[0022] Step S4, Coating and Drying: The composite adhesive is evenly coated on both sides of the pretreated flexible reinforced substrate at a coating amount of 30g / m². It is first dried at 85℃ for 12min, and then dried at 115℃ for 12min to obtain the prepreg.

[0023] Step S5, Composite Molding: The prepreg and 35μm thick electrolytic copper foil (Ra=0.5μm) are stacked in the structure of "copper foil-prepreg-copper foil", and placed in a hot press. The hot press is carried out at a temperature of 220℃ and a pressure of 2.0MPa for 45 minutes. After cooling, a flexible polyphenylene ether copper-clad laminate is obtained.

[0024] Example 2

[0025] Step S1, Preparation of modified polyphenylene ether resin: Mix 90g of polyphenylene ether resin with 10g of polyether sulfone, melt and stir at 165℃ for 50min, cool and then pulverize to obtain modified polyphenylene ether resin powder.

[0026] Step S2, Substrate Pretreatment: Polyimide fiber cloth is selected as the flexible reinforcing substrate, treated with 350W plasma for 18 min, then immersed in 1.5% γ-aminopropyltriethoxysilane ethanol aqueous solution for 35 min, and dried at 105℃ for 22 min for later use.

[0027] Step S3, preparation of adhesive solution: Mix 100g of modified polyphenylene ether resin powder, 8g of 4,4'-diaminodiphenyl sulfone, and 0.8g of accelerator triphenylphosphine, add a mixture of toluene and acetone to adjust the solid content to 45%, and stir evenly to obtain composite adhesive solution;

[0028] Step S4, Coating and Drying: The composite adhesive is evenly coated on both sides of the pretreated flexible reinforced substrate at a coating amount of 25g / m². It is first dried at 80℃ for 15min, and then dried at 110℃ for 15min to obtain the prepreg.

[0029] Step S5, Composite Molding: The prepreg and 50μm thick electrolytic copper foil (Ra=0.7μm) are stacked in the structure of "copper foil-prepreg-copper foil", and placed in a hot press. The hot press is carried out at a temperature of 230℃ and a pressure of 2.5MPa for 40 minutes. After cooling, a flexible polyphenylene ether copper-clad laminate is obtained.

[0030] Example 3

[0031] Step S1, Preparation of modified polyphenylene ether resin: 92g of polyphenylene ether resin and 8g of hydroxyl-terminated polybutadiene are mixed, melt-stirred at 175℃ for 35min, cooled and pulverized to obtain modified polyphenylene ether resin powder.

[0032] Step S2, Substrate Pretreatment: Polyimide fiber cloth is selected as the flexible reinforcing substrate, treated with 450W plasma for 12 min, then immersed in 2.5% γ-aminopropyltriethoxysilane ethanol aqueous solution for 25 min, and dried at 110℃ for 20 min for later use.

[0033] Step S3, preparation of adhesive solution: Mix 100g of modified polyphenylene ether resin powder, 12g of dicyandiamide and 1.2g of accelerator 2-methylimidazole, add a mixture of toluene and acetone to adjust the solid content to 55%, and stir evenly to obtain composite adhesive solution;

[0034] Step S4, Coating and Drying: The composite adhesive is evenly coated on both sides of the pretreated flexible reinforced substrate at a coating amount of 35g / m². It is first dried at 90℃ for 10min, and then dried at 120℃ for 10min to obtain the prepreg.

[0035] Step S5, Composite Molding: The prepreg and 25μm thick electrolytic copper foil (Ra=0.4μm) are stacked in the structure of "copper foil-prepreg-copper foil", and placed in a hot press. The hot press is carried out at a temperature of 210℃ and a pressure of 1.8MPa for 50 minutes. After cooling, a flexible polyphenylene ether copper-clad laminate is obtained.

[0036] Example 4

[0037] Step S1, Preparation of modified polyphenylene ether resin: 88g of polyphenylene ether resin and 12g of polyether sulfone were mixed, melted and stirred at 168℃ for 42min, cooled and then pulverized to obtain modified polyphenylene ether resin powder.

[0038] Step S2, Substrate Pretreatment: Polyimide fiber cloth is selected as the flexible reinforcing substrate, treated with 380W plasma for 16 min, then immersed in 1.8% γ-aminopropyltriethoxysilane ethanol aqueous solution for 32 min, and dried at 108℃ for 24 min for later use.

[0039] Step S3, preparation of adhesive solution: Mix 100g of modified polyphenylene ether resin powder, 9g of 4,4'-diaminodiphenyl sulfone, and 0.9g of accelerator triphenylphosphine, add a mixture of toluene and acetone to adjust the solid content to 48%, and stir evenly to obtain composite adhesive solution;

[0040] Step S4, Coating and Drying: The composite adhesive is uniformly coated on both sides of the pretreated flexible reinforced substrate at a coating amount of 28 g / m². It is first dried at 82°C for 14 min, and then dried at 112°C for 14 min to obtain the prepreg.

[0041] Step S5, Composite Molding: The prepreg and 60μm thick electrolytic copper foil (Ra=0.8μm) are stacked in the structure of "copper foil-prepreg-copper foil", and placed in a hot press. The hot press is carried out at a temperature of 225℃ and a pressure of 2.2MPa for 42 minutes. After cooling, a flexible polyphenylene ether copper-clad laminate is obtained.

[0042] Comparative Example 1

[0043] Step S1, Resin Preparation: Use unmodified polyphenylene ether resin directly, without adding a flexible modifier;

[0044] Step S2, Substrate Treatment: Select glass fiber cloth as the substrate, and dry it only at 100℃ for 20 minutes without plasma or coupling agent treatment;

[0045] Step S3, preparation of adhesive solution: Mix 100g of unmodified polyphenylene ether resin, 10g of dicyandiamide and 1g of accelerator 2-methylimidazole, add toluene to adjust the solid content to 50%, and stir evenly to obtain adhesive solution;

[0046] Step S4, Coating and Drying: Coat both sides of the fiberglass cloth with the adhesive solution at a rate of 30 g / m², and dry at 100°C for 20 min to obtain the prepreg.

[0047] Step S5, Composite molding: The prepreg and 35μm thick electrolytic copper foil are stacked in a "copper foil-prepreg-copper foil" structure, and hot-pressed at 220℃ and 2.0MPa for 45min. After cooling, a traditional polyphenylene ether copper-clad laminate is obtained.

[0048]

[0049] Therefore, the preparation method of this invention achieves a comprehensive breakthrough in the performance of copper-clad laminates through the synergistic effect of resin modification, dual pretreatment of the substrate, composite adhesive system, and two-stage drying process. Compared with Comparative Example 1, the product of this invention shows significant improvement in flexibility, with the bending radius reduced from ≥30mm to 6-8mm, copper foil peel strength increased by more than 77.8%, high-temperature stability improved from "obvious delamination" to "no delamination", dielectric loss reduced by more than 33.3%, and appearance bubble defects eliminated.

[0050] The technological value of each core process step is evident: resin modification is the foundation for improving flexibility; dual pretreatment of the substrate is key to enhancing bonding strength and high-temperature stability; and the mixed solvent and two-stage drying process ensure dielectric properties and appearance quality. Furthermore, this invention features a simple and controllable process, readily available raw materials, and industrial-scale mass production capability, providing a high-performance copper-clad laminate solution for flexible electronics and high-frequency communication fields, with broad application prospects.

[0051] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention. The scope of protection claimed by the appended claims and their equivalents is defined.

Claims

1. A method for preparing a flexible polyphenylene ether copper-clad laminate, characterized in that, Includes the following steps: Step S1, Preparation of modified polyphenylene ether resin: Mix polyphenylene ether resin and flexible modifier at a mass ratio of 80-95:5-20, melt and stir at 160-180℃ for 30-60 min, cool and then pulverize to obtain modified polyphenylene ether resin powder. Step S2, Substrate Pretreatment: Select polyimide fiber cloth as flexible reinforcing substrate, treat it with plasma for 10-20 min, then immerse it in coupling agent solution for 20-40 min, and dry it for later use; Step S3, preparation of adhesive solution: Mix the modified polyphenylene ether resin powder, curing agent and accelerator from step S1 at a mass ratio of 100:5-15:0.5-2, add organic solvent to adjust the solid content to 40-60%, and stir evenly to obtain composite adhesive solution; Step S4, Coating and Drying: The composite adhesive is evenly coated on both sides of the pretreated flexible reinforced substrate, with a coating amount of 20-40 g / m². First, it is dried at 80-90℃ for 10-15 min, and then dried at 110-120℃ for 10-15 min to obtain the prepreg. Step S5, Composite Molding: The prepreg and electrolytic copper foil are stacked in the structure of "copper foil-prepreg-copper foil", and placed in a hot press. The hot press is carried out at a temperature of 200-240℃ and a pressure of 1.5-3.0MPa for 30-60 minutes. After cooling, a flexible polyphenylene ether copper-clad laminate is obtained.

2. The preparation method according to claim 1, characterized in that, The flexible modifier mentioned in step S1 is hydroxyl-terminated polybutadiene or polyethersulfone with a molecular weight of 1000-5000.

3. The preparation method according to claim 1, characterized in that, The coupling agent solution mentioned in step S2 is an ethanol-water solution of γ-aminopropyltriethoxysilane, and the mass fraction of the coupling agent is 1-3%.

4. The preparation method according to claim 1, characterized in that, The curing agent in step S3 is dicyandiamide or 4,4'-diaminodiphenyl sulfone; the organic solvent is a mixture of toluene and acetone in a volume ratio of 1:1 to 3:

1.

5. The preparation method according to claim 1, characterized in that, The electrolytic copper foil mentioned in step S5 has a thickness of 12-70 μm and a surface roughness Ra of 0.3-1.0 μm.

6. The preparation method according to any one of claims 1-5, characterized in that, In step S2, the substrate drying temperature is 100-110℃ and the drying time is 20-30 min.

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