A high-dielectric polyphenyl ether composite dielectric copper-clad plate and a preparation method thereof

Abstract

The application relates to the technical field of dielectric materials, and particularly discloses a high-dielectric polyphenyl ether composite dielectric copper-clad plate and a preparation method thereof. The high-dielectric polyphenyl ether composite dielectric copper-clad plate has a three-layer sandwich structure of copper foil / substrate layer / copper foil, the substrate layer is formed by stacking a plurality of pieces of substrate material, and the raw material composition of the substrate material comprises 50-85 parts of modified inorganic fillers, 15-50 parts of polyphenyl ether resin and 40-150 parts of solvent according to weight fractions; the thickness of the substrate layer is 0.95-4.05 mm; the composite dielectric copper-clad plate material provided by the application has the characteristics of good peeling strength, high dielectric constant and ultra-low dielectric loss; the application has the advantages of simple preparation process, convenient operation and low equipment requirement, and is suitable for industrial production.

Description

Technical Field

[0001] This invention relates to the field of dielectric materials technology, and in particular to a high-dielectric polyphenylene ether composite dielectric copper-clad laminate and its preparation method. Background Technology

[0002] With the rapid development of portable communication devices, antennas, as the core components used to transmit or receive electromagnetic waves in wireless devices, are constantly being optimized and upgraded towards integration, miniaturization, lightweighting, and intelligence. Under the condition that the resonant frequency of the antenna remains unchanged, the larger the dielectric constant of the substrate material, the smaller the antenna size.

[0003] Polyphenylene ether resin has a dielectric constant between 2.6 and 2.8, which is close to that of polytetrafluoroethylene resin. It also has a lower molding and processing temperature and is widely used in the copper clad laminate manufacturing industry. Adding more than 50% of fillers with high dielectric constant to the polyphenylene ether resin matrix is ​​expected to obtain polyphenylene ether-based dielectric composite materials with high dielectric constant.

[0004] However, the existing high-frequency resin-based composite dielectric materials often have the following problems: (1) Excessive addition of functional ceramic fillers is usually accompanied by dispersion and agglomeration, which increases the internal defects of the composite material and leads to increased dielectric loss of the composite dielectric material, making it difficult for the composite dielectric material to have both high dielectric constant and low dielectric loss at the same time; (2) For copper clad laminate materials, their peel strength will also decrease with the increase of the amount of functional ceramic fillers added to the resin matrix, especially under high filler content, the peel strength of polyphenylene ether copper clad laminate materials is difficult to exceed 1.2 N / mm; (3) Existing high-frequency resin-based composite dielectric materials usually add low dielectric constant materials such as lubricants, toughening agents or electronic glass fiber cloth, which makes the dielectric constant of high dielectric polyphenylene ether composite materials prone to loss to a certain extent, and also leads to high overall dielectric loss of the composite material. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, the present invention provides a high-dielectric polyphenylene ether composite dielectric copper-clad laminate, which improves the dielectric constant of the composite material while reducing its dielectric loss.

[0006] A high-dielectric polyphenylene ether composite dielectric copper-clad laminate, wherein the copper-clad laminate has a three-layer sandwich structure of copper foil / substrate layer / copper foil, and the substrate layer is formed by stacking several substrate materials. The raw material composition of the substrate materials, by weight, includes: 50 to 85 parts of modified inorganic filler, 15 to 50 parts of polyphenylene ether resin, and 40 to 150 parts of solvent.

[0007] The modified inorganic filler is composed of the following raw materials in parts by weight:

[0008] 100 parts of inorganic filler;

[0009] 1.8 parts of silane coupling agent;

[0010] 100 to 200 parts ethanol;

[0011] The thickness of the substrate layer is 0.95 mm to 4.05 mm.

[0012] Adding high-filler-content, high-dielectric-constant functional fillers to a polymer matrix with low dielectric constant, with a functional filler content of ≥50%, can combine the advantages of two-phase or multi-phase materials, achieving a "1+1>2" effect and obtaining high-dielectric polymer matrix composites with excellent comprehensive performance. Compared with existing technologies, this application, apart from the matrix resin and high dielectric constant functional fillers, does not introduce other low dielectric constant materials such as fiberglass cloth and toughening agents. This avoids the generation of interface problems such as interphase porosity, voids, and interlayer bonding forces, as well as the risk of reducing the final dielectric constant of the composite material. The modified inorganic filler can improve the compatibility and dispersibility of inorganic fillers in the polyphenylene ether resin matrix, reduce the probability of filler accumulation in the resin matrix, reduce interfacial bonding defects between two phases, effectively improve the peel strength of copper clad laminate, and reduce the dielectric loss of composite material, making it suitable for fabricating miniaturized microwave antennas. The polyphenylene ether composite dielectric copper clad laminate of this invention can achieve a dielectric constant exceeding 28 and a dielectric loss of less than 0.0025 at a frequency of 10 GHz. At the same time, the dielectric constant-frequency response fluctuation can be as low as ±0.2, and the peel strength can be as high as 1.42 N / mm, thereby improving the dielectric constant of the composite material while reducing its dielectric loss.

[0013] Optionally, the inorganic filler is one or a mixture of two of titanates and inorganic oxides;

[0014] The titanate is one of calcium strontium titanate and strontium titanate;

[0015] The inorganic oxide is titanium dioxide;

[0016] The D50 of the inorganic filler is 0.5μm to 40μm.

[0017] Optionally, the preparation method of the modified inorganic filler includes the following steps:

[0018] The inorganic filler was mixed with a portion of ethanol in a certain proportion to obtain a suspension.

[0019] Add ammonia to the remaining ethanol and stir until the pH of the mixture is 11. Then add silane coupling agent to the mixture to obtain a pre-hydrolyzed solution.

[0020] The pre-hydrolyzed solution was stirred and hydrolyzed under water bath conditions to obtain a hydrolysate;

[0021] The hydrolysate was added to the suspension and mixed evenly to obtain a pretreated mixture;

[0022] The pretreated mixture was dried to obtain the modified inorganic filler.

[0023] Optionally, the mass ratio of the modified inorganic filler to the polyphenylene ether resin is (1-5.7):1.

[0024] Optionally, the polyphenylene ether resin is a powdered polyphenylene ether resin without end-group modification;

[0025] The molecular weight of the polyphenylene ether resin is greater than 19,000.

[0026] Optionally, the solvent is one or a combination of toluene, methyl ethyl ketone (MEK), and xylene.

[0027] Optionally, the thickness of the substrate material is 0.95 mm to 2.05 mm.

[0028] When the substrate material thickness exceeds 2mm, the dielectric constant of the composite dielectric material formed by hot pressing increases to a certain extent with the increase of the substrate material thickness; conversely, if a composite dielectric material is obtained by stacking and pressing several substrates with a thickness of less than 2mm, its dielectric constant remains stable and does not change significantly.

[0029] In another aspect, the present invention provides a method for preparing the above-mentioned high-dielectric polyphenylene ether composite dielectric copper-clad laminate, comprising the following steps:

[0030] S1. The polyphenylene ether resin and the modified inorganic filler are added to a ball mill jar in proportion and mixed to obtain a premix;

[0031] S2. The premix is ​​added to the solvent in batches and mixed evenly to obtain a mixed solution;

[0032] S3. Coat the mixed solution onto the release film and air dry to obtain an inorganic filler / polyphenylene ether composite film;

[0033] S4. The inorganic filler / polyphenylene ether composite film is pulverized and dried to obtain inorganic filler / polyphenylene ether composite film powder.

[0034] S5. The inorganic filler / polyphenylene ether composite film powder is evenly spread in a mold and hot-pressed to obtain a substrate material;

[0035] S6. The copper foil, substrate material and copper foil are sequentially laid in the mold and hot-pressed to obtain a high-dielectric polyphenylene ether composite dielectric copper-clad laminate.

[0036] Optionally, the high-dielectric polyphenylene ether composite dielectric copper-clad laminate is a flat plate.

[0037] Optionally, in steps S5 and S6, the hot pressing temperature is 235–275°C, the hot pressing pressure is 10 MPa–50 MPa, and the hot pressing time is 30 min–180 min.

[0038] To ensure that the surface and interior of the composite material can be fully heated and melted during molding, appropriate pressure can be applied to increase the fluidity of polyphenylene ether resin, improve the density of the substrate material, reduce dielectric loss, and increase the dielectric constant and peel strength of the substrate material.

[0039] The beneficial effects of this invention are as follows: This invention combines dry premixing and wet mixing to composite modified inorganic fillers with high dielectric constants with polyphenylene ether resin. This reduces filler agglomeration, resulting in a more uniformly dispersed polyphenylene ether composite material. The polyphenylene ether composite material is then processed and molded using a hot-pressing process to prepare a high-dielectric-constant polyphenylene ether composite dielectric copper-clad laminate material. Besides the matrix resin and high-dielectric-constant functional fillers, no other low-dielectric-constant materials such as fiberglass cloth or toughening agents are introduced, avoiding the risk of reducing the final dielectric constant of the composite material. The smaller phase composition also reduces the generation of interfacial problems such as pores, voids, and interlayer bonding forces between different phases in the composite material, thereby helping to reduce dielectric loss. Furthermore, the uniformly dispersed fillers help reduce the probability of interfacial defects and increase the continuity of the resin matrix, which not only reduces the dielectric loss of the dielectric substrate and improves the uniformity of the dielectric constant but also enhances the peel strength of the copper-clad laminate.

[0040] This invention obtains a high-dielectric polyphenylene ether-based composite dielectric copper-clad laminate material for high-frequency applications by premixing, secondary wet mixing, solvent removal, ball milling, drying, and hot pressing of polyphenylene ether resin and modified inorganic fillers. The amount of inorganic filler added is as high as 85%, and the preparation process is simple and easy to operate. This allows the polyphenylene ether composite dielectric copper-clad laminate to achieve a dielectric constant of over 28 and a dielectric loss of less than 0.0025 at a frequency of 10 GHz, thereby improving the dielectric constant of the composite material while reducing its dielectric loss. Attached Figure Description

[0041] Figure 1 The stable curves of dielectric constant versus frequency response of the high-dielectric polyphenylene ether composite dielectric copper-clad laminates of Examples 1-4 and Comparative Examples 1-4 of the present invention at 1-10 GHz.

[0042] Figure 2 The stable curves of dielectric loss versus frequency response of the high-dielectric polyphenylene ether composite dielectric copper-clad laminates of Examples 1-4 and Comparative Examples 1-4 of the present invention at 1-10 GHz.

[0043] Figure 3The stable curves of dielectric constant versus frequency response of the high-dielectric polyphenylene ether composite dielectric copper-clad laminates in Examples 6-8 of the present invention at 1-10 GHz;

[0044] Figure 4 The stable curves of dielectric loss versus frequency response of the high-dielectric polyphenylene ether composite dielectric copper-clad laminates in Examples 6-8 of the present invention at 1-10 GHz are shown.

[0045] Figure 5 This is a scanning electron microscope (SEM) image of a cross-section of the high-dielectric polyphenylene ether composite dielectric copper-clad laminate of Embodiment 3 of the present invention at 20K magnification. Detailed Implementation

[0046] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0047] The method for preparing the modified inorganic filler involved in this invention is as follows:

[0048] The preparation method of modified calcium strontium titanate includes the following steps:

[0049] 1) Add 1000g of calcium strontium titanate with a D50 of 20μm to 800g of ethanol and sonicate at room temperature for 30min to obtain a suspension;

[0050] 2) Add ammonia to 200g of ethanol and stir until the pH of the solution is 11. Then add 18g of KH550 to obtain a pre-hydrolyzed solution.

[0051] 3) The pre-hydrolyzed solution was stirred and hydrolyzed in a water bath at 50±5℃ for 30 min to obtain the hydrolysate;

[0052] 4) Add the hydrolysate to the suspension and sonicate for 1.5 h to obtain the pretreated mixture;

[0053] 5) Spread the pretreated mixture evenly on drying paper, air dry the ethanol, and then put it into an electric heating oven to dry at 120°C for 120 min to obtain modified calcium strontium titanate.

[0054] The preparation method of modified strontium titanate includes the following steps:

[0055] 1) Add 1000g of strontium titanate with a D50 of 40μm to 800g of ethanol and sonicate at room temperature for 30min to obtain a suspension;

[0056] 2) Add ammonia to 200g of ethanol and stir until the pH of the solution is 11. Then add 18g of KH550 to obtain a pre-hydrolyzed solution.

[0057] 3) The pre-hydrolyzed solution was stirred and hydrolyzed in a water bath at 50±5℃ for 30 min to obtain the hydrolysate;

[0058] 4) Add the hydrolysate to the suspension and sonicate for 1.5 h to obtain the pretreated mixture;

[0059] 5) Spread the pretreated mixture evenly on drying paper, air dry the ethanol, and then put it into an electric heating oven to dry at 120°C for 120 min to obtain modified strontium titanate.

[0060] The preparation method of modified titanium dioxide includes the following steps:

[0061] 1) Add 1000g of titanium dioxide with a D50 of 0.5μm to 800g of ethanol and sonicate at room temperature for 30min to obtain a suspension;

[0062] 2) Add ammonia to 200g of ethanol and stir until the pH of the solution is 11. Then add 18g of KH550 to obtain a pre-hydrolyzed solution.

[0063] 3) The pre-hydrolyzed solution was stirred and hydrolyzed in a water bath at 50±5℃ for 30 min to obtain the hydrolysate;

[0064] 4) Add the hydrolysate to the suspension and sonicate for 1.5 h to obtain the pretreated mixture;

[0065] 5) Spread the pretreated mixture evenly on drying paper, air dry the ethanol, and then put it into an electric heating oven to dry at 120℃ for 120 min to obtain modified titanium dioxide.

[0066] Example

[0067] Example 1

[0068] A high-dielectric polyphenylene ether composite dielectric copper-clad laminate is manufactured through the following steps:

[0069] S1. 315g of unmodified powdered polyphenylene ether resin with a molecular weight of 20000-23000 and 685g of modified calcium strontium titanate were placed in a ball mill jar and mixed with single zirconium balls with a diameter of 5mm at a ball-to-material ratio of 8:1 at a speed of 88r / min for 1h to obtain a premix.

[0070] S2. Add the premix to 1200g of toluene in three portions: 40% of the premix in the first portion, 30% in the second portion, and 30% in the third portion, with an interval of 10min between each addition. Stir and sonicate at 55±5℃ for 180±1min to obtain a mixed solution.

[0071] S3. Coat the mixed solution onto the release film, remove the solvent in a fume hood, and obtain the inorganic filler / polyphenylene ether composite film.

[0072] S4. The inorganic filler / polyphenylene ether composite film is pulverized in a ball mill to obtain inorganic filler / polyphenylene ether composite film powder with D50 of 40μm to 50μm. The inorganic filler / polyphenylene ether composite film powder is dried in an oven at 150±5℃ for 90min.

[0073] S5. Spread 55g of inorganic filler / polyphenylene ether composite film powder in the mold, and hot press for 30min at 270±5℃ and 10MPa to obtain a flat plate substrate material with a thickness of 1±0.05mm.

[0074] S6. Copper foil, a layer of substrate material and copper foil are sequentially laid in the mold. Under the conditions of 270±5℃ and 10MPa pressure, the copper foil is hot-pressed for 30 minutes to obtain a high-dielectric polyphenylene ether composite dielectric copper-clad laminate.

[0075] Example 2

[0076] A high-dielectric polyphenylene ether composite dielectric copper-clad laminate, which differs from Example 1 in that it is manufactured through the following steps:

[0077] S1. Place 200g of unmodified powdered polyphenylene ether resin with a molecular weight of 20,000 to 23,000 and 800g of modified calcium strontium titanate in a ball mill jar. Mix the mixture for 1 hour at a ball-to-material ratio of 8:1 using a single zirconium ball with a diameter of 5mm to obtain a premix.

[0078] S2. Add the premix to 1000g of toluene in three portions: 40% of the premix in the first portion, 30% in the second portion, and 30% in the third portion, with an interval of 10min between each addition. Stir and sonicate at 55±5℃ for 180±1min to obtain a mixed solution.

[0079] S3. Coat the mixed solution onto the release film, remove the solvent in a fume hood, and obtain the inorganic filler / polyphenylene ether composite film.

[0080] S4. The inorganic filler / polyphenylene ether composite film is pulverized in a ball mill to obtain inorganic filler / polyphenylene ether composite film powder with D50 of 15μm to 20μm. The inorganic filler / polyphenylene ether composite film powder is dried in an oven at 150±5℃ for 90min.

[0081] S5. Spread 65g of inorganic filler / polyphenylene ether composite film powder evenly in the mold, and hot press for 30min at 270±5℃ and 40MPa to obtain a flat plate substrate material with a thickness of 1±0.05mm.

[0082] S6. Copper foil, a layer of substrate material and copper foil are sequentially laid in the mold. Under the conditions of 270±5℃ and 40MPa, the copper foil is hot-pressed for 60min to obtain a high-dielectric polyphenylene ether composite dielectric copper-clad laminate.

[0083] Example 3

[0084] A high-dielectric polyphenylene ether composite dielectric copper-clad laminate, which differs from Example 1 in that it is manufactured through the following steps:

[0085] S1. 170g of unmodified powdered polyphenylene ether resin with a molecular weight of 20,000 to 23,000 and 830g of modified calcium strontium titanate were placed in a ball mill jar and mixed with single zirconium balls with a diameter of 5mm at a ball-to-material ratio of 8:1 at a speed of 88r / min for 1h to obtain a premix.

[0086] S2. Add the premix to 1000g of toluene in three portions: 40% of the premix in the first portion, 30% in the second portion, and 30% in the third portion, with an interval of 10min between each addition. Stir and sonicate at 55±5℃ for 180±1min to obtain a mixed solution.

[0087] S3. Coat the mixed solution onto the release film, remove the solvent in a fume hood, and obtain the inorganic filler / polyphenylene ether composite film.

[0088] S4. The inorganic filler / polyphenylene ether composite film is pulverized in a ball mill to obtain inorganic filler / polyphenylene ether composite film powder with D50 of 15μm to 20μm. The inorganic filler / polyphenylene ether composite film powder is dried in an oven at 150±5℃ for 90min.

[0089] S5. Spread 72g of inorganic filler / polyphenylene ether composite film powder in the mold, and hot press for 30min at 270±5℃ and 45MPa to obtain a flat plate substrate material with a thickness of 1±0.05mm.

[0090] S6. Copper foil, a layer of substrate material and copper foil are sequentially laid in the mold. Under the conditions of 270±5℃ and 45MPa pressure, the copper foil is hot-pressed for 30 minutes to obtain a high dielectric polyphenylene ether composite dielectric copper-clad laminate.

[0091] Example 4

[0092] A high-dielectric polyphenylene ether composite dielectric copper-clad laminate, which differs from Example 1 in that it is manufactured through the following steps:

[0093] S1. Place 150g of unmodified powdered polyphenylene ether resin with a molecular weight of 20,000 to 23,000 and 850g of modified calcium strontium titanate in a ball mill jar. Mix the mixture for 1 hour at a ball-to-material ratio of 8:1 using a single zirconium ball with a diameter of 5mm to obtain a premix.

[0094] S2. Add the premix to 1000g of toluene in three portions: 40% of the premix in the first portion, 30% in the second portion, and 30% in the third portion, with an interval of 10min between each addition. Stir and sonicate at 55±5℃ for 180±1min to obtain a mixed solution.

[0095] S3. Coat the mixed solution onto the release film, remove the solvent in a fume hood, and obtain the inorganic filler / polyphenylene ether composite film.

[0096] S4. The inorganic filler / polyphenylene ether composite film is pulverized in a ball mill to obtain inorganic filler / polyphenylene ether composite film powder with D50 of 10μm to 15μm. The inorganic filler / polyphenylene ether composite film powder is dried in an oven at 150±5℃ for 90min.

[0097] S5. Spread 158g of inorganic filler / polyphenylene ether composite film powder in the mold, and hot press for 60min at 270±5℃ and 48MPa to obtain a substrate material with a thickness of 2.0±0.05mm.

[0098] S6. Copper foil, a layer of substrate material and copper foil are sequentially laid in the mold. Under the conditions of 270±5℃ and 48MPa pressure, the copper foil is hot-pressed for 60 minutes to obtain a high-dielectric polyphenylene ether composite dielectric copper-clad laminate.

[0099] Example 5

[0100] A high-dielectric polyphenylene ether composite dielectric copper-clad laminate, which differs from Example 1 in that it is manufactured through the following steps:

[0101] S1. 315g of unmodified powdered polyphenylene ether resin with a molecular weight of 20000-23000 and 685g of modified calcium strontium titanate were placed in a ball mill jar and mixed with single zirconium balls with a diameter of 5mm at a ball-to-material ratio of 8:1 at a speed of 88r / min for 1h to obtain a premix.

[0102] S2. Add the premix to 1200g of toluene in three portions: 40% of the premix in the first portion, 30% in the second portion, and 30% in the third portion, with an interval of 10min between each addition. Stir and sonicate at 55±5℃ for 180±1min to obtain a mixed solution.

[0103] S3. Coat the mixed solution onto the release film, remove the solvent in a fume hood, and obtain the inorganic filler / polyphenylene ether composite film.

[0104] S4. The inorganic filler / polyphenylene ether composite film is pulverized in a ball mill to obtain inorganic filler / polyphenylene ether composite film powder with D50 of 40μm to 50μm. The inorganic filler / polyphenylene ether composite film powder is dried in an oven at 150±5℃ for 90min.

[0105] S5. Spread 55g of inorganic filler / polyphenylene ether composite film powder in the mold, and hot press for 30min at 270±5℃ and 10MPa to obtain a flat plate substrate material with a thickness of 1±0.05mm.

[0106] S6. Copper foil, four layers of substrate material with a thickness of 1±0.05mm and copper foil are sequentially laid in the mold. Under the conditions of 270±5℃ and 10MPa pressure, the substrate is hot-pressed for 90min to obtain a high dielectric polyphenylene ether composite dielectric copper-clad laminate.

[0107] Example 6

[0108] A high-dielectric polyphenylene ether composite dielectric copper-clad laminate, which differs from Example 1 in that it is manufactured through the following steps:

[0109] S1. Place 500g of unmodified powdered polyphenylene ether resin with a molecular weight of 20,000 to 23,000 and 500g of modified calcium strontium titanate in a ball mill jar. Mix the mixture for 1 hour at a ball-to-material ratio of 8:1 using a single zirconium ball with a diameter of 5mm to obtain a premix.

[0110] S2. Add the premix to 1500g of toluene in three portions: 40% of the premix in the first portion, 30% in the second portion, and 30% in the third portion, with an interval of 10min between each addition. Stir and sonicate at 55±5℃ for 180±1min to obtain a mixed solution.

[0111] S3. Coat the mixed solution onto the release film, remove the solvent in a fume hood, and obtain the inorganic filler / polyphenylene ether composite film.

[0112] S4. The inorganic filler / polyphenylene ether composite film is pulverized in a ball mill to obtain inorganic filler / polyphenylene ether composite film powder with D50 of 48μm~55μm. The inorganic filler / polyphenylene ether composite film powder is dried in an oven at 150±5℃ for 90min.

[0113] S5. Spread 55g of inorganic filler / polyphenylene ether composite film powder evenly in the mold, and hot press for 30min at 270±5℃ and 10MPa to obtain a substrate material with a thickness of 1±0.05mm.

[0114] S6. Copper foil, a layer of substrate material and copper foil are sequentially laid in the mold. Under the conditions of 270±5℃ and 10MPa pressure, the copper foil is hot-pressed for 30 minutes to obtain a high-dielectric polyphenylene ether composite dielectric copper-clad laminate.

[0115] Example 7

[0116] A high-dielectric polyphenylene ether composite dielectric copper-clad laminate, which differs from Example 1 in that it is manufactured through the following steps:

[0117] S1. Place 500g of polyphenylene ether resin with a molecular weight of 20000-23000 and 500g of modified strontium titanate in a ball mill jar, and mix them for 1 hour at a ball-to-material ratio of 8:1 using single zirconium balls with a diameter of 5mm to obtain a premix.

[0118] S2. Add the premix to 1500g of toluene in three portions: 40% of the premix in the first portion, 30% in the second portion, and 30% in the third portion, with an interval of 10min between each addition. Stir and sonicate at 55±5℃ for 180±1min to obtain a mixed solution.

[0119] S3. Coat the mixed solution onto the release film, remove the solvent in a fume hood, and obtain the inorganic filler / polyphenylene ether composite film.

[0120] S4. The inorganic filler / polyphenylene ether composite film is pulverized in a ball mill to obtain inorganic filler / polyphenylene ether composite film powder with D50 of 70μm~75μm. The inorganic filler / polyphenylene ether composite film powder is dried in an oven at 150±5℃ for 90min.

[0121] S5. Spread 55g of inorganic filler / polyphenylene ether composite film powder evenly in the mold, and hot press for 30min at 270±5℃ and 10MPa to obtain a substrate material with a thickness of 1±0.05mm.

[0122] S6. Copper foil, a layer of substrate material and copper foil are sequentially laid in the mold. Under the conditions of 270±5℃ and 10MPa pressure, the copper foil is hot-pressed for 30 minutes to obtain a high-dielectric polyphenylene ether composite dielectric copper-clad laminate.

[0123] Example 8

[0124] A high-dielectric polyphenylene ether composite dielectric copper-clad laminate, which differs from Example 1 in that it is manufactured through the following steps:

[0125] S1. Place 500g of polyphenylene ether resin with a molecular weight of 20000-23000 and 500g of modified titanium dioxide in a ball mill jar, and mix them for 1 hour at a ball-to-material ratio of 8:1 using single zirconium balls with a diameter of 5mm to obtain a premix.

[0126] S2. Add the premix to 1500g of toluene in three portions: 40% of the premix in the first portion, 30% in the second portion, and 30% in the third portion, with an interval of 10min between each addition. Stir and sonicate at 55±5℃ for 180±1min to obtain a mixed solution.

[0127] S3. Coat the mixed solution onto the release film, remove the solvent in a fume hood, and obtain the inorganic filler / polyphenylene ether composite film.

[0128] S4. The inorganic filler / polyphenylene ether composite film is pulverized in a ball mill to obtain inorganic filler / polyphenylene ether composite film powder with D50 of 50μm to 55μm. The inorganic filler / polyphenylene ether composite film powder is dried in an oven at 150±5℃ for 90min.

[0129] S5. Spread 45g of inorganic filler / polyphenylene ether composite film powder evenly in the mold, and hot press for 30min at 270±5℃ and 10MPa to obtain a substrate material with a thickness of 1±0.05mm.

[0130] S6. Copper foil, a layer of substrate material and copper foil are sequentially laid in the mold. Under the conditions of 270±5℃ and 10MPa pressure, the copper foil is hot-pressed for 30 minutes to obtain a high-dielectric polyphenylene ether composite dielectric copper-clad laminate.

[0131] Comparative Example

[0132] Comparative Example 1

[0133] A high-dielectric polyphenylene ether composite dielectric copper-clad laminate, which differs from Example 2 in that it is manufactured through the following steps:

[0134] S1. Add 800g of modified calcium strontium titanate to 1000g of toluene, stir and sonicate at 55±5℃ for 30±1min to obtain a suspension;

[0135] S2. Add 200g of unterminated polyphenylene ether resin powder with a molecular weight of 20000-23000 to the suspension in three portions. The first addition is 40% of the mass of the polyphenylene ether resin, the second addition is 30%, and the third addition is 30%, with an interval of 10min between each addition. Stir and sonicate at 55±5℃ for 180±1min to obtain a mixed solution.

[0136] S3. Coat the mixed solution onto the release film, remove the solvent in a fume hood, and obtain the inorganic filler / polyphenylene ether composite film.

[0137] S4. The inorganic filler / polyphenylene ether composite film is pulverized in a ball mill to obtain inorganic filler / polyphenylene ether composite film powder with D50 of 15μm to 20μm. The inorganic filler / polyphenylene ether composite film powder is dried in an oven at 150±5℃ for 90min.

[0138] S5. Spread 65g of inorganic filler / polyphenylene ether composite film powder evenly in the mold, and hot press for 30min at 270±5℃ and 40MPa to obtain a flat plate substrate material with a thickness of 1±0.05mm.

[0139] S6. Copper foil, substrate material and copper foil are sequentially laid in the mold. Under the conditions of 270±5℃ and 40MPa, the copper foil is hot-pressed for 60min to obtain a high dielectric polyphenylene ether composite dielectric copper-clad laminate.

[0140] Comparative Example 2

[0141] A high-dielectric polyphenylene ether composite dielectric copper-clad laminate, which differs from Example 2 in that it is manufactured through the following steps:

[0142] S1. Place 150g of unmodified powdered polyphenylene ether resin with a molecular weight of 20,000 to 23,000 and 800g of modified calcium strontium titanate in a ball mill jar. Mix the mixture for 1 hour at a ball-to-material ratio of 8:1 using a single zirconium ball with a diameter of 5mm to obtain a premix.

[0143] S2. Add the premix to 1000g of toluene in three portions: 40% of the premix in the first portion, 30% in the second portion, and 30% in the third portion, with an interval of 10min between each addition. Stir and sonicate at 55±5℃ for 60±1min. Then add 50g of styrene-butadiene rubber, stir and sonicate for 120±1min to obtain a mixed solution.

[0144] S3. Coat the mixed solution onto the release film, remove the solvent in a fume hood, and obtain the inorganic filler / polyphenylene ether composite film.

[0145] S4. The inorganic filler / polyphenylene ether composite film is pulverized in a ball mill to obtain inorganic filler / polyphenylene ether composite film powder with D50 of 15μm to 20μm. The inorganic filler / polyphenylene ether composite film powder is dried in an oven at 150±5℃ for 90min.

[0146] S5. The inorganic filler / polyphenylene ether composite film powder is spread evenly in the mold and hot-pressed for 30 minutes at 245±5℃ and 40MPa to obtain a flat plate substrate material with a thickness of 1±0.05mm.

[0147] S6. Copper foil, a layer of substrate material, and copper foil are sequentially laid in the mold. Under the conditions of 245±5℃ and 40MPa pressure, the copper-clad laminate with high dielectric polyphenylene ether composite dielectric substrate material is obtained for 60 minutes.

[0148] Comparative Example 3

[0149] A high-dielectric polyphenylene ether composite dielectric copper-clad laminate, which differs from Example 2 in that it is manufactured through the following steps:

[0150] S1. Place 200g of unmodified powdered polyphenylene ether resin with a molecular weight of 20,000 to 23,000 and 800g of modified calcium strontium titanate in a ball mill jar. Mix the mixture for 1 hour at a ball-to-material ratio of 8:1 using a single zirconium ball with a diameter of 5mm to obtain a premix.

[0151] S2. Add the premix to 1000g of toluene in three portions: 40% of the premix in the first portion, 30% in the second portion, and 30% in the third portion, with an interval of 10min between each addition. Stir and sonicate at 55±5℃ for 180±1min to obtain a mixed solution.

[0152] S3. The mixed solution is impregnated onto 1080 cloth and dried in an oven at 150±5℃ for 90 min to obtain a resin-impregnated composite material with a solid content of 66.3%.

[0153] S4. Cut the impregnated composite material into sheets, and lay copper foil, sheet impregnated composite material and copper foil in sequence in the mold. Under the conditions of 270±5℃ and 40MPa, hot press for 60min to obtain a high-dielectric polyphenylene ether composite dielectric copper-clad laminate as the substrate material.

[0154] Comparative Example 4

[0155] A high-dielectric polyphenylene ether composite dielectric copper-clad laminate, which differs from Example 2 in that it is manufactured through the following steps:

[0156] S1. Place 200g of unmodified powdered polyphenylene ether resin with a molecular weight of 20,000 to 23,000 and 800g of modified calcium strontium titanate in a ball mill jar. Mix the mixture for 1 hour at a ball-to-material ratio of 8:1 using a single zirconium ball with a diameter of 5mm to obtain a premix.

[0157] S2. Add the premix to 1000g of toluene in three portions: 40% of the premix in the first portion, 30% in the second portion, and 30% in the third portion, with an interval of 10min between each addition. Stir and sonicate at 55±5℃ for 180±1min to obtain a mixed solution.

[0158] S3. The mixed solution is impregnated onto nonwoven fabric and dried in an oven at 150±5℃ for 90 min to obtain a resin-impregnated composite material with a solid content of 91.8%.

[0159] S4. Cut the impregnated composite material into sheets, and lay copper foil, sheet impregnated composite material and copper foil in sequence in the mold. Under the conditions of 270±5℃ and 40MPa, hot press for 60min to obtain a high-dielectric polyphenylene ether composite dielectric copper-clad laminate as the substrate material.

[0160] Comparative Example 5

[0161] A high-dielectric polyphenylene ether composite dielectric copper-clad laminate, which differs from Example 5 in that it is manufactured through the following steps:

[0162] S1. 315g of unmodified powdered polyphenylene ether resin with a molecular weight of 20000-23000 and 685g of modified calcium strontium titanate were placed in a ball mill jar and mixed with single zirconium balls with a diameter of 5mm at a ball-to-material ratio of 8:1 at a speed of 88r / min for 1h to obtain a premix.

[0163] S2. Add the premix to 1200g of toluene in three portions: 40% of the premix in the first portion, 30% in the second portion, and 30% in the third portion, with an interval of 10min between each addition. Stir and sonicate at 55±5℃ for 180±1min to obtain a mixed solution.

[0164] S3. Coat the mixed solution onto the release film, remove the solvent in a fume hood, and obtain the inorganic filler / polyphenylene ether composite film.

[0165] S4. The inorganic filler / polyphenylene ether composite film is pulverized in a ball mill to obtain inorganic filler / polyphenylene ether composite film powder with D50 of 40μm to 50μm. The inorganic filler / polyphenylene ether composite film powder is dried in an oven at 150±5℃ for 90min.

[0166] S5. Spread 223g of inorganic filler / polyphenylene ether composite film powder in the mold, and hot press for 90min at 270±5℃ and 10MPa to obtain a flat plate substrate material with a thickness of 4±0.05mm.

[0167] S6. Copper foil, a layer of 4±0.05mm substrate material, and copper foil are sequentially laid in the mold. Under the conditions of 270±5℃ and 10MPa pressure, the copper foil is hot-pressed for 90min to obtain a high-dielectric polyphenylene ether composite dielectric copper-clad laminate.

[0168] Comparative Example 6

[0169] A high-dielectric polyphenylene ether composite dielectric copper-clad laminate differs from Example 4 in that 150g of unmodified powdered polyphenylene ether resin with a molecular weight of 20,000-23,000 is mixed evenly with 850g of modified calcium strontium titanate and then fed into an injection molding machine. The polyphenylene ether composite material is prepared by melting and extrusion. The temperature is set to 280 / 290 / 290 / 300 / 290℃ and the mold temperature is 150℃.

[0170] Performance testing

[0171] The following performance tests were conducted on the high-dielectric polyphenylene ether composite dielectric copper-clad laminates provided in Examples 1-8 and Comparative Examples 1-5 of this invention:

[0172] Peel strength: The peel strength of the high dielectric polyphenylene ether composite dielectric copper clad laminates of Examples 1-8 and Comparative Examples 1-5 under normal conditions was tested according to GB / T 4722-2017. The dielectric properties at 3GHz and 10GHz were tested according to the IPC-TM650 2.5.5.5 stripline method. The specific test results are shown in Table 1.

[0173] Dielectric stability: The dielectric constant and dielectric loss stability of Examples 1-4 and Comparative Examples 1-4 at 1-10 GHz were tested at room temperature using the IPC-TM650 2.5.5.5 stripline method. Specific test results are shown in [link to test results]. Figure 1 and Figure 2 Examples 6-8 show the stability of dielectric constant and dielectric loss with frequency response from 1 to 10 GHz. Specific test results are available in [link to test results]. Figure 3 and Figure 4 .

[0174] The dispersibility of inorganic fillers in polyphenylene ether resin: The microstructure of the cross-section of the high-dielectric polyphenylene ether composite material prepared in Example 3 was observed using a Zeiss Gemini SEM 500 field emission scanning electron microscope to verify the dispersibility of the high-filler inorganic filler in the resin matrix. See [link to Zeiss Gemini SEM 500 field emission scanning electron microscope]. Figure 5 .

[0175] Temperature resistance: High dielectric polyphenylene ether composite dielectric copper clad laminates of 50mm×30mm size for Examples 1-8 and Comparative Examples 1-5 were taken respectively. Three samples were taken from each example and comparative example. The samples were dried in an oven at 180℃ for 15 minutes and the appearance of the boards was observed. The specific test results are shown in Table 1.

[0176] Table 1 Performance Results

[0177]

[0178]

[0179] The composite material of Comparative Example 6 exhibited melt fracture and insufficient mold filling during the preparation process, and the resulting substrate material had a rough appearance and porosity defects.

[0180] As shown in Table 1, the high-dielectric polyphenylene ether composite dielectric copper-clad laminate prepared by the method of this invention exhibits a dielectric constant as high as 28.5986 at a high frequency of 10 GHz, while still maintaining an ultra-low loss of 0.0021 and a high peel strength of 1.42 N / mm. Furthermore, with the same proportion of inorganic fillers, the high-dielectric polyphenylene ether composite dielectric copper-clad laminate material prepared by this method (such as Example 2) is superior to Comparative Examples 1-4 in both dielectric properties and peel strength. The raw materials of the high-dielectric polyphenylene ether composite dielectric copper-clad laminate of this invention, apart from the matrix resin and high-dielectric-constant functional fillers, do not introduce other low-dielectric-constant materials such as fiberglass cloth and toughening agents, thus avoiding the risk of reducing the final dielectric constant of the composite material. In addition, a smaller phase composition can also reduce the generation of interfacial problems such as interphase porosity, voids, and interlayer bonding forces in the composite material, thereby contributing to the reduction of dielectric loss of the composite material. Furthermore, comparing the dielectric constant data of Example 1, Example 5 and Comparative Example 5, it can be seen that the dielectric constants of the thin and thick (thickness > 2.0 mm) high-dielectric polyphenylene ether composite dielectric copper clad laminates obtained by the preparation method of the present invention are almost consistent. This avoids the problem of dielectric constant shift caused by different thicknesses and improves the dielectric constant stability of the high-dielectric polyphenylene ether composite dielectric copper clad laminate.

[0181] from Figure 1 and Figure 2It can be seen that the high-dielectric polyphenylene ether composite dielectric copper-clad laminate material prepared by this method exhibits superior overall performance in terms of dielectric constant, dielectric loss, and dielectric constant-frequency response stability. A large span between the D50 and D90 of the inorganic filler can affect the dielectric stability and dielectric loss of the product. Premixing the inorganic filler and polyphenylene ether resin using ball milling achieves preliminary mixing and also reduces the span between the D50 and D90 of the inorganic filler, thus stabilizing the dielectric constant. Then, wet mixing is used to further mix and disperse the inorganic filler and polyphenylene ether resin, resulting in a more uniformly dispersed polyphenylene ether composite material, thereby obtaining a composite dielectric material with superior performance.

[0182] from Figure 3 and Figure 4 It can be seen that the high-dielectric polyphenylene ether composite dielectric copper clad laminate material prepared by this method can achieve the same or similar dielectric constants for the inorganic fillers mentioned in this invention without considering dielectric loss, thus exhibiting a certain degree of interchangeability and reducing the limitation of the uniqueness of raw materials.

[0183] from Figure 5 It can be seen that, even when the inorganic filler content is as high as 83%, the composite material prepared by this invention does not exhibit obvious inorganic filler agglomeration or large void defects in the composite matrix, and generally shows good inorganic filler dispersion and dense substrate microstructure. Uniformly dispersed fillers help reduce the probability of interface defects and increase the continuity of the resin matrix, thereby reducing the dielectric loss of the dielectric substrate, improving the uniformity of the dielectric constant, and enhancing the peel strength of the copper clad laminate, which is consistent with the previous results.

[0184] 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-dielectric polyphenylene ether composite dielectric copper-clad laminate, characterized in that, The copper-clad laminate has a three-layer sandwich structure of copper foil / substrate layer / copper foil. The substrate layer is formed by stacking several substrate materials. According to the weight parts, the substrate material is composed of the following raw materials: 50 to 85 parts of modified inorganic filler, 15 to 50 parts of polyphenylene ether resin and 40 to 150 parts of solvent. The modified inorganic filler is composed of the following raw materials in parts by weight: 100 parts of inorganic filler; 1.8 parts of silane coupling agent; 100 parts of ethanol; The thickness of the substrate layer is 0.95 mm to 4.05 mm; The preparation method of the modified inorganic filler includes the following steps: The inorganic filler was mixed with a portion of ethanol in a certain proportion to obtain a suspension. Add ammonia to the remaining ethanol and stir until the pH of the mixture is 11. Then add silane coupling agent to the mixture to obtain a pre-hydrolyzed solution. The pre-hydrolyzed solution was stirred and hydrolyzed under water bath conditions to obtain a hydrolysate; The hydrolysate was added to the suspension and mixed evenly to obtain a pretreated mixture; The pretreated mixture was dried to obtain the modified inorganic filler; The thickness of the substrate material is 1 ± 0.05 mm; The preparation of the high-dielectric polyphenylene ether composite dielectric copper-clad laminate includes the following steps: S1. The polyphenylene ether resin and the modified inorganic filler are added to a ball mill jar in proportion and mixed to obtain a premix; S2. The premix is ​​added to the solvent in batches and mixed evenly to obtain a mixed solution; S3. Coat the mixed solution onto the release film and air dry to obtain an inorganic filler / polyphenylene ether composite film; S4. The inorganic filler / polyphenylene ether composite film is pulverized and dried to obtain inorganic filler / polyphenylene ether composite film powder. S5. The inorganic filler / polyphenylene ether composite film powder is evenly spread in a mold and hot-pressed to obtain a substrate material; S6. The copper foil, substrate material and copper foil are sequentially laid in the mold and hot-pressed to obtain a high-dielectric polyphenylene ether composite dielectric copper-clad laminate. The inorganic filler is one or a mixture of two of titanates and inorganic oxides; The titanate is one of calcium strontium titanate and strontium titanate; The inorganic oxide is titanium dioxide; The D50 of the inorganic filler is 0.5μm to 40μm.

2. The high-dielectric polyphenylene ether composite dielectric copper-clad laminate according to claim 1, characterized in that, The mass ratio of the modified inorganic filler to the polyphenylene ether resin is 1:

1.

3. The high-dielectric polyphenylene ether composite dielectric copper-clad laminate according to claim 1, characterized in that, The polyphenylene ether resin is a powdered polyphenylene ether resin without end-group modification; The molecular weight of the polyphenylene ether resin is greater than 19,000.

4. The high-dielectric polyphenylene ether composite dielectric copper-clad laminate according to claim 1, characterized in that, The solvent is one or a combination of toluene, methyl ethyl ketone (MEK), and xylene.

5. The high-dielectric polyphenylene ether composite dielectric copper-clad laminate according to claim 1, characterized in that, The high-dielectric polyphenylene ether composite dielectric copper-clad laminate is a flat plate.

6. The high-dielectric polyphenylene ether composite dielectric copper-clad laminate according to claim 1, characterized in that, In steps S5 and S6, the hot pressing temperature is 235℃~275℃, the hot pressing pressure is 10MPa~50MPa, and the hot pressing time is 30min~180min.

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