High-dielectric polyphenyl ether composite dielectric copper-clad plate and preparation method thereof

Abstract

The invention 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 is of a copper foil / substrate layer / copper foil three-layer sandwich structure, a substrate layer is formed by overlapping a plurality of substrate materials, and the substrate materials comprise the following raw materials in parts by weight: 50-85 parts of modified inorganic filler, 15-50 parts of polyphenyl ether resin and 40-150 parts of solvent; the thickness of the substrate layer ranges from 0.95 mm to 4.05 mm; the composite dielectric copper-clad plate material provided by the invention has the characteristics of good peel strength, high dielectric constant and ultralow dielectric loss; the method has the advantages of simple preparation process, convenience in operation and low equipment requirement, and is suitable for industrial production.

Description

Technical Field

[0001] The invention relates to the technical field of dielectric materials, and in particular to a high-dielectric polyphenylene ether composite dielectric copper-clad plate and a preparation method thereof. Background Art

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

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

[0004] However, the existing high-frequency resin-based composite dielectric material technology often has the following problems: (1) Excessive addition of functional ceramic fillers is usually accompanied by dispersion and agglomeration problems, which causes an increase in internal defects of the composite material and leads to an increase in the dielectric loss of the composite dielectric material, making it difficult for the composite dielectric material to have both a high dielectric constant and a low dielectric loss; (2) For copper-clad laminate materials, their peel strength will also decrease with the increase in the amount of functional ceramic fillers added to the resin matrix. Especially at high filling amounts, the peel strength of polyphenylene ether copper-clad laminate materials is difficult to exceed 1.2N / 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 causes the overall dielectric loss of the composite material to be relatively high. Summary of the invention

[0005] In order to overcome the deficiencies of the prior art, the present invention provides a high dielectric polyphenylene ether composite dielectric copper clad laminate, so as to improve the dielectric constant of the composite material while reducing its dielectric loss.

[0006] A high dielectric polyphenylene ether composite dielectric copper-clad laminate, the copper-clad laminate is a three-layer sandwich structure of copper foil / substrate layer / copper foil, the substrate layer is formed by stacking a plurality of substrate materials, and the raw materials of the substrate material are composed of 50 to 85 parts of modified inorganic filler, 15 to 50 parts of polyphenylene ether resin and 40 to 150 parts of solvent in parts by weight;

[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 of ethanol;

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

[0012] Adding a high-dielectric-constant functional filler with a high filling amount to a low-dielectric-constant polymer matrix, with the functional filler accounting for ≥50%, can combine the advantages of two-phase or multi-phase materials, achieve the effect of "1+1>2", and obtain a high-dielectric polymer-based composite material with excellent comprehensive performance. Compared with the prior art, in addition to the matrix resin and high dielectric constant functional fillers, the present application does not introduce other low dielectric constant materials such as glass fiber cloth and toughening agent, thereby avoiding the generation of interface problems such as pores, voids and interlayer bonding between different phases and the risk of reducing the final dielectric constant of the composite material; the modified inorganic filler can improve the compatibility and dispersibility of the inorganic filler in the polyphenylene ether resin matrix, reduce the stacking probability of the filler in the resin matrix, reduce the interface bonding defects of the two-phase material, effectively improve the peeling strength of the copper clad laminate, reduce the dielectric loss of the composite material, and is suitable for preparing miniaturized microwave antennas; the polyphenylene ether composite dielectric copper clad laminate of the present invention can have a dielectric constant of more than 28 at a frequency of 10 GHz, and a dielectric loss of less than 0.0025, while the dielectric constant-frequency response volatility can be as low as ±0.2, and the peel strength can be as high as 1.42 N / mm, thereby reducing its dielectric loss while improving the dielectric constant of the composite material.

[0013] Optionally, the inorganic filler is one or a mixture of titanate and inorganic oxide;

[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 0.5 μm to 40 μm.

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

[0018] Mixing the inorganic filler with part of ethanol in proportion to obtain a suspension;

[0019] Adding ammonia water to the remaining ethanol and stirring evenly until the pH of the mixed solution is 11, and then adding a silane coupling agent to the mixed solution to obtain a pre-hydrolysis solution;

[0020] The pre-hydrolysis solution is stirred and hydrolyzed in a water bath to obtain a hydrolyzate;

[0021] Adding the hydrolyzate to the suspension and mixing evenly to obtain a pretreated mixture;

[0022] The pretreated mixture is dried to obtain a 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 terminal group modification;

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

[0026] Optionally, the solvent is one or more combinations of toluene, butanone and xylene.

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

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

[0029] Another aspect of 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, adding the polyphenylene ether resin and the modified inorganic filler into a ball mill according to a proportion and mixing them to obtain a premix;

[0031] S2, adding the premix into the solvent in batches and mixing evenly to obtain a mixed solution;

[0032] S3, coating the mixed solution on a release film and air-drying the mixture to obtain an inorganic filler / polyphenylene ether composite film;

[0033] S4, crushing and drying the inorganic filler / polyphenylene ether composite film to obtain an inorganic filler / polyphenylene ether composite film powder;

[0034] S5, evenly laying the inorganic filler / polyphenylene ether composite film powder in a mold and hot pressing it to obtain a substrate material;

[0035] S6, sequentially laying the copper foil, substrate material and copper foil in a mold for hot pressing 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 step S5 and step S6, the temperature of the hot pressing is 235-275° C., the pressure of the hot pressing is 10 MPa-50 MPa, and the time of the hot pressing is 30 min-180 min.

[0038] Ensure that the surface and inner lining of the composite material can be fully heated and melted during pressing. When the inner lining and surface of the composite material are fully heated and melted, appropriate pressure can be used to increase the fluidity of the polyphenylene ether resin and improve the density of the substrate material, which is beneficial to reduce dielectric loss and improve the dielectric constant and peel strength of the substrate material.

[0039] The beneficial effects of the present invention are as follows: the present invention combines a modified inorganic filler with a high dielectric constant with a polyphenylene ether resin by a combination of dry premixing and wet mixing, which can reduce the agglomeration of the filler to obtain a polyphenylene ether composite material with a more uniform filler dispersion, and then uses a hot pressing process to process and shape the polyphenylene ether composite material into a high dielectric polyphenylene ether composite medium copper-clad laminate material. In addition to the matrix resin and the high dielectric constant functional filler, other low dielectric constant materials such as glass fiber cloth and toughening agent are not introduced, thereby avoiding the risk of reducing the final dielectric constant of the composite material; fewer phase compositions can also reduce the generation of interface problems such as pores, voids and interlayer bonding between different phases in the composite material, thereby helping to reduce the dielectric loss of the composite material. In addition, the uniformly dispersed filler is conducive to reducing the probability of interface defects and increasing the continuity of the resin matrix, which can not only reduce the dielectric loss of the dielectric substrate, improve the uniformity of the dielectric constant, but also improve the peeling strength of the copper-clad laminate.

[0040] The invention premixes polyphenylene ether resin and modified inorganic filler, performs secondary wet mixing, removes solvent, performs ball milling, dries, performs hot pressing and other treatments to obtain a high-frequency high-dielectric polyphenylene ether-based composite dielectric copper-clad laminate material, wherein the addition amount of the inorganic filler is as high as 85%, and the preparation process is simple and the operation is convenient, so that the dielectric constant of the polyphenylene ether composite dielectric copper-clad laminate at a frequency of 10 GHz can exceed 28, and the dielectric loss is less than 0.0025, thereby reducing the dielectric loss of the composite material while improving the dielectric constant. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 The stable curve of the dielectric constant of the high dielectric polyphenylene ether composite dielectric copper-clad laminates of Examples 1 to 4 of the present invention and Comparative Examples 1 to 4 at 1 to 10 GHz as a function of frequency response;

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

[0043] Figure 3The stable curve of the dielectric constant of the high dielectric polyphenylene ether composite dielectric copper-clad laminate of Examples 6 to 8 of the present invention at 1 to 10 GHz as a function of frequency response;

[0044] Figure 4 The stable curve of dielectric loss versus frequency response of the high dielectric polyphenylene ether composite dielectric copper-clad laminates of Examples 6 to 8 of the present invention at 1 to 10 GHz;

[0045] Figure 5 This is a scanning electron microscope image of the cross section of the high dielectric polyphenylene ether composite dielectric copper-clad laminate of Example 3 of the present invention at 20K magnification. DETAILED DESCRIPTION

[0046] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of 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.

[0047] The preparation method of the modified inorganic filler according to the present invention is as follows:

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

[0049] 1) adding 1000 g of calcium strontium titanate with a D50 of 20 μm into 800 g of ethanol and stirring the mixture ultrasonically at room temperature for 30 min to obtain a suspension;

[0050] 2) Add ammonia water to 200 g of ethanol and stir until the pH of the solution is 11, then add 18 g of KH550 to obtain a pre-hydrolysis solution;

[0051] 3) stirring and hydrolyzing the pre-hydrolyzed solution in a water bath at 50±5°C for 30 min to obtain a hydrolyzed solution;

[0052] 4) adding the hydrolyzate to the suspension and stirring for 1.5 h to obtain a pretreated mixture;

[0053] 5) The pretreated mixture was evenly spread on drying paper to air-dry the ethanol, and then placed in an electric heating oven and dried at 120° C. for 120 min to obtain modified calcium strontium titanate.

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

[0055] 1) adding 1000 g of strontium titanate with a D50 of 40 μm into 800 g of ethanol and stirring the mixture ultrasonically at room temperature for 30 min to obtain a suspension;

[0056] 2) Add ammonia water to 200 g of ethanol and stir until the pH of the solution is 11, then add 18 g of KH550 to obtain a pre-hydrolysis solution;

[0057] 3) stirring and hydrolyzing the pre-hydrolyzed solution in a water bath at 50±5°C for 30 min to obtain a hydrolyzed solution;

[0058] 4) adding the hydrolyzate to the suspension and stirring for 1.5 h to obtain a pretreated mixture;

[0059] 5) The pretreated mixture was evenly spread on drying paper to air-dry the ethanol, and then placed in an electric heating oven and dried at 120° C. for 120 min to obtain modified strontium titanate.

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

[0061] 1) adding 1000 g of titanium dioxide with a D50 of 0.5 μm into 800 g of ethanol and stirring the mixture under ultrasonic conditions for 30 min at room temperature to obtain a suspension;

[0062] 2) Add ammonia water to 200 g of ethanol and stir until the pH of the solution is 11, then add 18 g of KH550 to obtain a pre-hydrolysis solution;

[0063] 3) stirring and hydrolyzing the pre-hydrolyzed solution in a water bath at 50±5°C for 30 min to obtain a hydrolyzed solution;

[0064] 4) adding the hydrolyzate to the suspension and stirring for 1.5 h to obtain a pretreated mixture;

[0065] 5) The pretreated mixture was evenly spread on drying paper to air-dry the ethanol, and then placed in an electric heating oven and dried at 120° C. 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 by the following steps:

[0069] S1. 315 g of a non-end-group modified powdered polyphenylene ether resin with a molecular weight of 20,000 to 23,000 and 685 g of modified calcium strontium titanate are placed in a ball mill, and mixed at a speed of 88 r / min for 1 h using a single zirconium ball with a diameter of 5 mm at a ball-to-material ratio of 8:1 to obtain a premix;

[0070] S2, adding the premix to 1200g toluene three times, adding 40% of the premix by weight for the first time, 30% for the second time, and 30% for the third time, each time with an interval of 10min, and stirring and ultrasonically oscillating at 55±5°C for 180±1min to obtain a mixed solution;

[0071] S3, coating the mixed solution on a release film, and removing the solvent in a fume hood to obtain an inorganic filler / polyphenylene ether composite film;

[0072] S4, grinding the inorganic filler / polyphenylene ether composite film in a ball mill to obtain an inorganic filler / polyphenylene ether composite film powder with a D50 of 40 μm to 50 μm, and drying the inorganic filler / polyphenylene ether composite film powder in an oven at 150±5° C. for 90 min;

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

[0074] S6. Lay copper foil, a layer of substrate material and copper foil in the mold in sequence, and hot press for 30 minutes at 270±5°C and a pressure of 10 MPa 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 is different from Example 1 in that it is made by the following steps:

[0077] S1, placing 200 g of a powdered polyphenylene ether resin having a molecular weight of 20,000 to 23,000 and not modified by end groups and 800 g of modified calcium strontium titanate in a ball mill, mixing the materials at a speed of 88 r / min for 1 h using a single zirconium ball having a diameter of 5 mm at a ball-to-material ratio of 8:1 to obtain a premix;

[0078] S2, adding the premix to 1000g toluene three times, adding 40% of the premix by weight for the first time, 30% for the second time, and 30% for the third time, each time with an interval of 10min, and stirring at 55±5°C and ultrasonically oscillating for 180±1min to obtain a mixed solution;

[0079] S3, coating the mixed solution on a release film, and removing the solvent in a fume hood to obtain an inorganic filler / polyphenylene ether composite film;

[0080] S4, grinding the inorganic filler / polyphenylene ether composite film in a ball mill to obtain an inorganic filler / polyphenylene ether composite film powder with a D50 of 15 μm to 20 μm, and drying the inorganic filler / polyphenylene ether composite film powder in an oven at 150±5° C. for 90 min;

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

[0082] S6. Lay copper foil, a layer of substrate material and copper foil in the mold in sequence, and hot press for 60 minutes at 270±5°C and a pressure of 40MPa 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 is different from Example 1 in that it is made by the following steps:

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

[0086] S2, adding the premix to 1000g toluene three times, adding 40% of the premix by weight for the first time, 30% for the second time, and 30% for the third time, each time with an interval of 10min, and stirring at 55±5°C and ultrasonically oscillating for 180±1min to obtain a mixed solution;

[0087] S3, coating the mixed solution on a release film, and removing the solvent in a fume hood to obtain an inorganic filler / polyphenylene ether composite film;

[0088] S4, grinding the inorganic filler / polyphenylene ether composite film in a ball mill to obtain an inorganic filler / polyphenylene ether composite film powder with a D50 of 15 μm to 20 μm, and drying the inorganic filler / polyphenylene ether composite film powder in an oven at 150±5° C. for 90 min;

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

[0090] S6. Lay copper foil, a layer of substrate material and copper foil in the mold in sequence, and hot press for 30 minutes at 270±5°C and a pressure of 45MPa 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 is different from Example 1 in that it is made by the following steps:

[0093] S1. 150 g of a non-end-group modified powdered polyphenylene ether resin with a molecular weight of 20,000 to 23,000 and 850 g of modified calcium strontium titanate are placed in a ball mill, and mixed at a speed of 88 r / min for 1 hour using a single zirconium ball with a diameter of 5 mm at a ball-to-material ratio of 8:1 to obtain a premix;

[0094] S2, adding the premix to 1000g toluene three times, adding 40% of the premix by weight for the first time, 30% for the second time, and 30% for the third time, each time with an interval of 10min, and stirring at 55±5°C and ultrasonically oscillating for 180±1min to obtain a mixed solution;

[0095] S3, coating the mixed solution on a release film, and removing the solvent in a fume hood to obtain an inorganic filler / polyphenylene ether composite film;

[0096] S4, grinding the inorganic filler / polyphenylene ether composite film in a ball mill to obtain an inorganic filler / polyphenylene ether composite film powder with a D50 of 10 μm to 15 μm, and drying the inorganic filler / polyphenylene ether composite film powder in an oven at 150±5° C. for 90 min;

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

[0098] S6. Lay copper foil, a layer of substrate material and copper foil in the mold in sequence, and hot press for 60 minutes at 270±5°C and a pressure of 48MPa 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 is different from Example 1 in that it is made by the following steps:

[0101] S1. 315 g of a non-end-group modified powdered polyphenylene ether resin with a molecular weight of 20,000 to 23,000 and 685 g of modified calcium strontium titanate are placed in a ball mill, and mixed at a speed of 88 r / min for 1 h using a single zirconium ball with a diameter of 5 mm at a ball-to-material ratio of 8:1 to obtain a premix;

[0102] S2, adding the premix to 1200g toluene three times, adding 40% of the premix by weight for the first time, 30% for the second time, and 30% for the third time, each time with an interval of 10min, and stirring and ultrasonically oscillating at 55±5°C for 180±1min to obtain a mixed solution;

[0103] S3, coating the mixed solution on a release film, and removing the solvent in a fume hood to obtain an inorganic filler / polyphenylene ether composite film;

[0104] S4, grinding the inorganic filler / polyphenylene ether composite film in a ball mill to obtain an inorganic filler / polyphenylene ether composite film powder with a D50 of 40 μm to 50 μm, and drying the inorganic filler / polyphenylene ether composite film powder in an oven at 150±5° C. for 90 min;

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

[0106] S6. Lay copper foil, four layers of substrate material with a thickness of 1±0.05 mm, and copper foil in the mold in sequence, and hot press for 90 minutes at 270±5°C and a pressure of 10 MPa 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 is different from Example 1 in that it is made by the following steps:

[0109] S1. 500 g of a powdered polyphenylene ether resin having a molecular weight of 20,000 to 23,000 and not modified by end groups and 500 g of modified calcium strontium titanate are placed in a ball mill, and mixed at a speed of 88 r / min for 1 h using a single zirconium ball having a diameter of 5 mm at a ball-to-material ratio of 8:1 to obtain a premix;

[0110] S2, adding the premix to 1500g toluene three times, adding 40% of the premix by weight for the first time, 30% for the second time, and 30% for the third time, each time with an interval of 10min, and stirring and ultrasonically oscillating at 55±5°C for 180±1min to obtain a mixed solution;

[0111] S3, coating the mixed solution on a release film, and removing the solvent in a fume hood to obtain an inorganic filler / polyphenylene ether composite film;

[0112] S4, grinding the inorganic filler / polyphenylene ether composite film in a ball mill to obtain an inorganic filler / polyphenylene ether composite film powder with a D50 of 48 μm to 55 μm, and drying the inorganic filler / polyphenylene ether composite film powder in an oven at 150±5° C. for 90 min;

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

[0114] S6. Lay copper foil, a layer of substrate material and copper foil in the mold in sequence, and hot press for 30 minutes at 270±5°C and a pressure of 10 MPa 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 is different from Example 1 in that it is made by the following steps:

[0117] S1. 500 g of polyphenylene ether resin with a molecular weight of 20,000 to 23,000 and 500 g of modified strontium titanate are placed in a ball mill, and mixed at a speed of 88 r / min for 1 h using a single zirconium ball with a diameter of 5 mm at a ball-to-material ratio of 8:1 to obtain a premix;

[0118] S2, adding the premix to 1500g toluene three times, adding 40% of the premix by weight for the first time, 30% for the second time, and 30% for the third time, each time with an interval of 10min, and stirring and ultrasonically oscillating at 55±5°C for 180±1min to obtain a mixed solution;

[0119] S3, coating the mixed solution on a release film, and removing the solvent in a fume hood to obtain an inorganic filler / polyphenylene ether composite film;

[0120] S4, grinding the inorganic filler / polyphenylene ether composite film in a ball mill to obtain an inorganic filler / polyphenylene ether composite film powder with a D50 of 70 μm to 75 μm, and drying the inorganic filler / polyphenylene ether composite film powder in an oven at 150±5° C. for 90 min;

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

[0122] S6. Lay copper foil, a layer of substrate material and copper foil in the mold in sequence, and hot press for 30 minutes at 270±5°C and a pressure of 10 MPa 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 is different from Example 1 in that it is made by the following steps:

[0125] S1. 500 g of polyphenylene ether resin with a molecular weight of 20,000 to 23,000 and 500 g of modified titanium dioxide are placed in a ball mill, and mixed at a speed of 88 r / min for 1 h using a single zirconium ball with a diameter of 5 mm at a ball-to-material ratio of 8:1 to obtain a premix;

[0126] S2, adding the premix to 1500g toluene three times, adding 40% of the premix by weight for the first time, 30% for the second time, and 30% for the third time, each time with an interval of 10min, and stirring and ultrasonically oscillating at 55±5°C for 180±1min to obtain a mixed solution;

[0127] S3, coating the mixed solution on a release film, and removing the solvent in a fume hood to obtain an inorganic filler / polyphenylene ether composite film;

[0128] S4, grinding the inorganic filler / polyphenylene ether composite film in a ball mill to obtain an inorganic filler / polyphenylene ether composite film powder with a D50 of 50 μm to 55 μm, and drying the inorganic filler / polyphenylene ether composite film powder in an oven at 150±5° C. for 90 min;

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

[0130] S6. Lay copper foil, a layer of substrate material and copper foil in the mold in sequence, and hot press for 30 minutes at 270±5°C and a pressure of 10 MPa 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 is different from Example 2 in that it is made by the following steps:

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

[0135] S2, adding 200g of a non-end-group modified powdered polyphenylene ether resin with a molecular weight of 20000-23000 to the suspension three times, adding 40% of the mass of the polyphenylene ether resin for the first time, 30% for the second time, and 30% for the third time, each time with an interval of 10min, and stirring at 55±5°C and ultrasonically oscillating for 180±1min to obtain a mixed solution;

[0136] S3, coating the mixed solution on a release film, and removing the solvent in a fume hood to obtain an inorganic filler / polyphenylene ether composite film;

[0137] S4, grinding the inorganic filler / polyphenylene ether composite film in a ball mill to obtain an inorganic filler / polyphenylene ether composite film powder with a D50 of 15 μm to 20 μm, and drying the inorganic filler / polyphenylene ether composite film powder in an oven at 150±5° C. for 90 min;

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

[0139] S6. Lay copper foil, substrate material and copper foil in the mold in sequence, and hot press for 60 minutes at 270±5°C and a pressure of 40MPa 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 is different from Example 2 in that it is made by the following steps:

[0142] S1. 150 g of a non-end-group modified powdered polyphenylene ether resin with a molecular weight of 20,000 to 23,000 and 800 g of modified calcium strontium titanate are placed in a ball mill, and mixed at a speed of 88 r / min for 1 h using a single zirconium ball with a diameter of 5 mm at a ball-to-material ratio of 8:1 to obtain a premix;

[0143] S2, the premix is ​​added to 1000g toluene three times, 40% of the premix is ​​added for the first time, 30% is added for the second time, and 30% is added for the third time, each time is separated by 10min, and stirred at 55±5°C, ultrasonically oscillated for 60±1min, and then 50g of styrene-butadiene rubber is added, stirred and ultrasonically oscillated for 120±1min to obtain a mixed solution;

[0144] S3, coating the mixed solution on a release film, and removing the solvent in a fume hood to obtain an inorganic filler / polyphenylene ether composite film;

[0145] S4, grinding the inorganic filler / polyphenylene ether composite film in a ball mill to obtain an inorganic filler / polyphenylene ether composite film powder with a D50 of 15 μm to 20 μm, and drying the inorganic filler / polyphenylene ether composite film powder in an oven at 150±5° C. for 90 min;

[0146] S5, spreading the inorganic filler / polyphenylene ether composite film powder in a mold, and hot pressing for 30 minutes at 245±5°C and a pressure of 40MPa to obtain a flat plate substrate material with a thickness of 1±0.05mm;

[0147] S6. Lay copper foil, a layer of substrate material and copper foil in the mold in sequence, and hot press for 60 minutes at 245±5°C and a pressure of 40MPa to obtain a high dielectric polyphenylene ether composite dielectric copper-clad laminate of the substrate material.

[0148] Comparative Example 3

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

[0150] S1, placing 200 g of a powdered polyphenylene ether resin having a molecular weight of 20,000 to 23,000 and not modified by end groups and 800 g of modified calcium strontium titanate in a ball mill, mixing the materials at a speed of 88 r / min for 1 h using a single zirconium ball having a diameter of 5 mm at a ball-to-material ratio of 8:1 to obtain a premix;

[0151] S2, adding the premix to 1000g toluene three times, adding 40% of the premix by weight for the first time, 30% for the second time, and 30% for the third time, each time with an interval of 10min, and stirring at 55±5°C and ultrasonically oscillating for 180±1min to obtain a mixed solution;

[0152] S3, impregnating the mixed solution on 1080 cloth, and drying in an oven at 150±5°C for 90 min to obtain an impregnated composite material with a solid content of 66.3%;

[0153] S4. Cut the impregnated composite material into sheets, and lay copper foil, sheet-like impregnated composite material and copper foil in a mold in sequence, and hot press for 60 minutes at 270±5°C and a pressure of 40MPa to obtain a substrate material high dielectric polyphenylene ether composite medium copper clad laminate.

[0154] Comparative Example 4

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

[0156] S1, placing 200 g of a powdered polyphenylene ether resin having a molecular weight of 20,000 to 23,000 and not modified by end groups and 800 g of modified calcium strontium titanate in a ball mill, mixing the materials at a speed of 88 r / min for 1 h using a single zirconium ball having a diameter of 5 mm at a ball-to-material ratio of 8:1 to obtain a premix;

[0157] S2, adding the premix to 1000g toluene three times, adding 40% of the premix by weight for the first time, 30% for the second time, and 30% for the third time, each time with an interval of 10min, and stirring at 55±5°C and ultrasonically oscillating for 180±1min to obtain a mixed solution;

[0158] S3, impregnating the mixed solution on a non-woven fabric, and drying in an oven at 150±5° C. for 90 min to obtain an impregnated composite material with a solid content of 91.8%;

[0159] S4. Cut the impregnated composite material into sheets, and lay copper foil, sheet-like impregnated composite material and copper foil in a mold in sequence, and hot press for 60 minutes at 270±5°C and a pressure of 40MPa to obtain a substrate material high dielectric polyphenylene ether composite medium copper clad laminate.

[0160] Comparative Example 5

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

[0162] S1. 315 g of a non-end-group modified powdered polyphenylene ether resin with a molecular weight of 20,000 to 23,000 and 685 g of modified calcium strontium titanate are placed in a ball mill, and mixed at a speed of 88 r / min for 1 h using a single zirconium ball with a diameter of 5 mm at a ball-to-material ratio of 8:1 to obtain a premix;

[0163] S2, adding the premix to 1200g toluene three times, adding 40% of the premix by weight for the first time, 30% for the second time, and 30% for the third time, each time with an interval of 10min, and stirring and ultrasonically oscillating at 55±5°C for 180±1min to obtain a mixed solution;

[0164] S3, coating the mixed solution on a release film, and removing the solvent in a fume hood to obtain an inorganic filler / polyphenylene ether composite film;

[0165] S4, grinding the inorganic filler / polyphenylene ether composite film in a ball mill to obtain an inorganic filler / polyphenylene ether composite film powder with a D50 of 40 μm to 50 μm, and drying the inorganic filler / polyphenylene ether composite film powder in an oven at 150±5° C. for 90 min;

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

[0167] S6. Lay copper foil, a layer of 4±0.05 mm substrate material and copper foil in the mold in sequence, and hot press for 90 minutes at 270±5°C and a pressure of 10 MPa to obtain a high dielectric polyphenylene ether composite dielectric copper-clad laminate.

[0168] Comparative Example 6

[0169] A high dielectric polyphenylene ether composite medium copper-clad laminate, which is different from Example 4 in that 150 g of a powdered polyphenylene ether resin with a molecular weight of 20,000 to 23,000 and not modified by end groups is evenly mixed with 850 g of modified calcium strontium titanate and put into an injection molding machine to prepare a polyphenylene ether composite material through melting and extrusion; the temperature is set to 280 / 290 / 290 / 300 / 290°C and the mold temperature is 150°C.

[0170] Performance Testing

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

[0172] Peel strength: The peel strength of the high dielectric polyphenylene ether composite dielectric copper clad laminates of Examples 1 to 8 and Comparative Examples 1 to 5 under normal conditions was tested according to GB / T 4722-2017, and the dielectric properties at 3 GHz and 10 GHz 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 stability of the dielectric constant and dielectric loss of Examples 1 to 4 and Comparative Examples 1 to 4 at 1 to 10 GHz with frequency response was tested at room temperature according to the IPC-TM650 2.5.5.5 stripline method. For specific test results, see Figure 1 and Figure 2 ; The stability of the dielectric constant and dielectric loss with frequency response at 1 to 10 GHz in Examples 6 to 8, see the specific test results Figure 3 and Figure 4 .

[0174] Dispersion of inorganic fillers in polyphenylene ether resin: The cross-section of the high dielectric polyphenylene ether composite material prepared in Example 3 was observed by Zeiss Gemini SEM 500 field emission scanning electron microscope to verify the dispersion of high-filling inorganic fillers in the resin matrix. Figure 5 .

[0175] Temperature resistance: Take 50mm×30mm high dielectric polyphenylene ether composite copper-clad laminates of Examples 1 to 8 and Comparative Examples 1 to 5, respectively, 3 samples of each Example and Comparative Example, dry them in an oven at 180°C for 15 minutes, and observe the appearance of the board. The specific test results are shown in Table 1.

[0176] Table 1 Performance results

[0177]

[0178]

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

[0180] It can be seen from Table 1 that the high dielectric polyphenylene ether composite dielectric copper-clad laminate obtained by the preparation method of the present invention has a dielectric constant of up to 28.5986 at a high frequency of 10 GHz, while still having an ultra-low loss of 0.0021 and a high peel strength of 1.42 N / mm; in addition, when the proportion of inorganic fillers is the same, the high dielectric polyphenylene ether composite dielectric copper-clad laminate material (such as Example 2) prepared by the present method is superior to Comparative Examples 1 to 4 in terms of both dielectric properties and peel strength. In addition to the matrix resin and the high dielectric constant functional filler, the raw materials of the high dielectric polyphenylene ether composite dielectric copper-clad laminate of the present invention do not introduce other low dielectric constant materials such as glass fiber cloth and toughening agent, thereby avoiding the risk of reducing the final dielectric constant of the composite material; in addition, fewer phase compositions can also reduce the generation of interface problems such as pores, voids and interlayer bonding forces between different phases in the composite material, thereby facilitating the reduction of the dielectric loss of the composite material. In addition, by comparing the dielectric constant data of Example 1, Example 5 and Comparative Example 5, it can be seen that the dielectric constants of the high dielectric polyphenylene ether composite dielectric copper-clad laminate thin plate and thick plate (thickness > 2.0 mm) obtained by the preparation method of the present invention are almost consistent, which avoids the dielectric constant offset problem 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 shows relatively excellent performance in terms of dielectric constant and dielectric loss as well as dielectric constant-frequency response stability. If the span between D50 and D90 of the inorganic filler is too large, it will affect the dielectric stability and dielectric loss of the product. The inorganic filler and polyphenylene ether resin are pre-mixed by ball milling, which can achieve the purpose of preliminary mixing and reduce the span between D50 and D90 of the inorganic filler, thereby stabilizing the dielectric constant. The inorganic filler and polyphenylene ether resin are then further mixed and dispersed by wet mixing to obtain a polyphenylene ether composite material with a more uniform filler dispersion, thereby obtaining a composite dielectric material with better 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, without considering the dielectric loss, the inorganic fillers mentioned in the present invention can achieve the same or similar dielectric constants, have a certain interchangeability, and reduce the limitation of the uniqueness of the raw materials.

[0183] from Figure 5 It can be seen that even when the inorganic filler accounts for 83% of the composite material prepared by the present invention, there is still no obvious agglomeration of inorganic fillers and large void defects in the composite material matrix, and the overall inorganic filler dispersion and substrate microstructure density are good. Uniformly dispersed fillers are conducive to reducing the probability of interface defects and increasing the continuity of the resin matrix, thereby reducing the dielectric loss of the dielectric substrate, improving the uniformity of the dielectric constant and increasing the peel strength of the copper clad laminate, which is consistent with the previous results.

[0184] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in 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 is a three-layer sandwich structure of copper foil / substrate layer / copper foil, wherein the substrate layer is formed by stacking a plurality of substrate materials, and the raw materials of the substrate material are composed of 50 to 85 parts of modified inorganic filler, 15 to 50 parts of polyphenylene ether resin, and 40 to 150 parts of solvent in terms of weight parts; 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.

2. A high dielectric polyphenylene ether composite dielectric copper-clad laminate according to claim 1, characterized in that: The inorganic filler is one or a mixture of titanate and inorganic oxide; The titanate is one of calcium strontium titanate and strontium titanate; The inorganic oxide is titanium dioxide; The D50 of the inorganic filler is 0.5 μm to 40 μm.

3. The high dielectric polyphenylene ether composite dielectric copper-clad laminate according to claim 1, characterized in that: The preparation method of the modified inorganic filler comprises the following steps: Mixing the inorganic filler with part of ethanol in proportion to obtain a suspension; Adding ammonia water to the remaining ethanol and stirring evenly until the pH of the mixed solution is 11, and then adding a silane coupling agent to the mixed solution to obtain a pre-hydrolysis solution; The pre-hydrolysis solution is stirred and hydrolyzed in a water bath to obtain a hydrolyzate; Adding the hydrolyzate to the suspension and mixing evenly to obtain a pretreated mixture; The pretreated mixture is dried to obtain a modified inorganic filler.

4. 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 (1-5.7):

1.

5. 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 terminal group modification; The molecular weight of the polyphenylene ether resin is greater than 19,000.

6. The high dielectric polyphenylene ether composite dielectric copper-clad laminate according to claim 1, characterized in that: The solvent is one or more combinations of toluene, butanone and xylene.

7. The high dielectric polyphenylene ether composite dielectric copper-clad laminate according to claim 1, characterized in that: The thickness of the substrate material is 0.95 mm to 2.05 mm.

8. A method for preparing a high dielectric polyphenylene ether composite dielectric copper-clad laminate, for preparing the high dielectric polyphenylene ether composite dielectric copper-clad laminate as claimed in any one of claims 1 to 7, characterized in that: The steps include: S1, adding the polyphenylene ether resin and the modified inorganic filler into a ball mill according to a proportion and mixing them to obtain a premix; S2, adding the premix into the solvent in batches and mixing evenly to obtain a mixed solution; S3, coating the mixed solution on a release film and air-drying the mixture to obtain an inorganic filler / polyphenylene ether composite film; S4, crushing and drying the inorganic filler / polyphenylene ether composite film to obtain an inorganic filler / polyphenylene ether composite film powder; S5, evenly laying the inorganic filler / polyphenylene ether composite film powder in a mold and hot pressing it to obtain a substrate material; S6, sequentially laying the copper foil, substrate material and copper foil in a mold for hot pressing to obtain a high dielectric polyphenylene ether composite dielectric copper-clad laminate.

9. The method for preparing a high dielectric polyphenylene ether composite dielectric copper-clad laminate according to claim 8, characterized in that: The high dielectric polyphenylene ether composite dielectric copper-clad laminate is a flat plate.

10. The method for preparing a high dielectric polyphenylene ether composite dielectric copper-clad laminate according to claim 8, characterized in that: In step S5 and step S6, the temperature of the hot pressing is 235° C. to 275° C., the pressure of the hot pressing is 10 MPa to 50 MPa, and the time of the hot pressing is 30 min to 180 min.

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