Nonwoven prepreg, metal foil-clad laminate, and printed circuit board

Abstract

The present invention provides a nonwoven prepreg, a metal foil-clad laminate, and a printed circuit board. The nonwoven prepreg includes a fluorine-containing resin adhesive nonwoven fabric and a fluorine-containing resin composition. The fluorine-containing resin adhesive nonwoven fabric includes an adhesive that is a fluorine-containing resin emulsion and inorganic fibers. The fluorine-containing resin composition includes, by weight parts, 30 to 100 parts of a fluorine-containing resin emulsion and 0 to 70 parts of an inorganic filler. The nonwoven prepreg according to the present invention and the copper-clad laminate including the same have excellent dielectric properties and a low coefficient of thermal expansion, so that the copper-clad laminate can meet the requirements for the performance of copper-clad laminate materials in the high-frequency communication field.

Description

Technical Field

[0001] The present invention belongs to the technical field of communication materials, and specifically relates to non-woven prepregs, metal-clad laminates, and printed circuit boards.

Background Art

[0002] As one of the important basic materials in the fields of electronic communication and information industry, copper-clad laminates are widely applied in fields such as mobile phones, personal computers, vending machines, communication base stations, satellites, and wearable devices, pilotless vehicles, drones, and smart robots. Due to their excellent properties such as low dielectric loss, high thermal stability, and chemical stability, fluorine-containing resins represented by polytetrafluoroethylene (PTFE) are ideal base materials for manufacturing copper-clad laminates. Since the 1950s of the previous century, researchers have gradually improved the manufacturing process of PTFE-based copper-clad laminates by continuously optimizing the formulation and parameters.

[0003] Since fluorine-containing resins have high flexibility in the polymer chain, it is usually necessary to introduce inorganic materials to improve the mechanical strength of fluorine-containing resin-based copper-clad laminates. For example, CN104175686A discloses a method for manufacturing a circuit PTFE composite dielectric substrate for microwaves. The method first mixes a fluororesin emulsion, an inorganic filler, and a thickener to obtain a stable and uniform dispersion, and then applies the dispersion to a releaseable substrate, bakes it, separates the substrate from the resin layer, overlaps the separated resin layer and copper foil, and laminates and sinters them at a high temperature to obtain a double-sided copper foil-coated PTFE composite dielectric substrate. Here, the inorganic filler is preferably silica and / or titanium dioxide. CN101838431A discloses a fluororesin mixture and a copper-clad laminate manufactured using the same. The fluororesin mixture includes a polytetrafluoroethylene perfluoroalkyl vinyl ether emulsion, a polytetrafluoroethylene emulsion, an inorganic filler, and a diluent, and the inorganic filler is silicon fine powder, kaolin, or titanium white.

[0004] Since fluorine-containing resins have high flexibility in the polymer chain, it is usually necessary to introduce a glass cloth reinforcing material to improve the mechanical strength of fluorine-containing resin copper-clad laminates. The woven structure in the warp and weft directions of the glass cloth may cause non-uniformity in the dielectric properties at different locations of the copper-clad laminate. Also, the use of glass cloth limits the addition of a large amount of inorganic fillers into the fluororesin matrix. For example, in US4225180A, microfibers and inorganic fillers are sequentially mixed into a PTFE emulsion, and through steps such as filtration-drying, a fluorine-containing resin mixture is obtained, which is pressed into a sheet to obtain a fluorine-containing resin-based copper-clad laminate not reinforced with glass cloth.

[0005] Therefore, developing a copper-clad laminate with excellent dielectric properties, coefficient of thermal expansion, and mechanical strength has become an urgent problem to be solved in this field.

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0006] In view of the deficiencies in the prior art, an object of the present invention is to provide a non-woven prepreg, a metal foil copper-clad laminate, and a printed circuit board. The prepreg includes a fluorine-containing resin adhesive non-woven fabric and a fluorine-containing resin composition, and the copper-clad laminate manufactured from the non-woven prepreg has excellent dielectric properties, coefficient of thermal expansion, and mechanical strength.

MEANS FOR SOLVING THE PROBLEMS

[0007] To achieve the object, the present invention has taken the following technical measures. On one aspect, the present invention provides a non-woven prepreg including a fluorine-containing resin adhesive non-woven fabric and a fluorine-containing resin composition, wherein the fluorine-containing resin adhesive non-woven fabric includes an adhesive that is a fluorine-containing resin emulsion and inorganic fibers, and the fluorine-containing resin composition includes, by weight parts, 30 to 100 parts of a fluorine-containing resin emulsion and 10 to 70 parts of an inorganic filler.

[0008] By using a fluorine-containing resin emulsion adhesive, the non-woven fabric has low dielectric loss, good uniformity, consistent thickness, consistent anisotropic distribution of fibers, high tensile strength, and when impregnating with a low dielectric loss resin, many dielectric fillers can be added to manufacture a low dielectric loss high-frequency copper-clad laminate. The copper-clad laminate obtained by manufacturing from a prepreg by blending a non-woven fabric made of an adhesive containing a fluorine-containing resin emulsion with a fluorine-containing resin emulsion and an inorganic filler has excellent dielectric properties, coefficient of thermal expansion, and mechanical strength.

[0009] In the present invention, the fluorine-containing resin composition contains, by weight part, 30 to 100 parts of a fluorine-containing resin emulsion, for example, 30 parts, 32 parts, 34 parts, 36 parts, 38 parts, 40 parts, 42 parts, 44 parts, 46 parts, 48 parts, 50 parts, 52 parts, 54 parts, 56 parts, 58 parts, 60 parts, 62 parts, 64 parts, 68 parts, 70 parts, 72 parts, 74 parts, 80 parts, 86 parts, 88 parts, 90 parts, 94 parts, 96 parts, 98 parts, 100 parts, etc. may be used.

[0010] The fluorine-containing resin composition contains, by weight part, 10 to 70 parts of an inorganic filler, for example, 10 parts, 16 parts, 18 parts, 20 parts, 24 parts, 26 parts, 30 parts, 32 parts, 34 parts, 36 parts, 38 parts, 40 parts, 42 parts, 44 parts, 46 parts, 48 parts, 50 parts, 52 parts, 54 parts, 56 parts, 58 parts, 60 parts, 62 parts, 64 parts, 66 parts, 68 parts, etc. may be used.

[0011] In the present invention, the fluorine-containing resin emulsion in the adhesive and the fluorine-containing resin emulsion in the fluorine-containing resin composition are each independently selected from any one or at least a combination of two kinds of polytetrafluoroethylene emulsion, polyperfluoroethylene propylene emulsion, polyvinylidene fluoride emulsion, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer emulsion, ethylene-tetrafluoroethylene copolymer emulsion, polychlorotrifluoroethylene emulsion or ethylene-chlorotrifluoroethylene copolymer emulsion.

[0012] Preferably, the weight percentage of the inorganic fibers in the fluorine-containing resin adhesive nonwoven fabric is 60 to 95% (for example, 60%, 62%, 65%, 68%, 70%, 73%, 75%, 78%, 80%, 83%, 85%, 88%, 90%, 93% or 95%), and the weight percentage of the adhesive is 5 to 40% (for example, 5%, 8%, 10%, 15%, 18%, 20%, 23%, 25%, 28%, 30%, 33%, 35%, 38% or 40%). In the present invention, if the weight percentage of the adhesive is too low, the adhesive cannot form a continuous film, and the strength of the nonwoven fabric will be low. If the weight percentage of the adhesive is too high, there will be many cavities inside the nonwoven fabric, many defects, the strength of the nonwoven fabric will be low, and it will further affect the dielectric loss and adhesiveness.

[0013] Preferably, the solid content of the fluorine-containing resin emulsion is 30 to 70%, for example, 30%, 35%, 38%, 40%, 45%, 50%, 55%, 60%, 65% or 70%.

[0014] Preferably, among the fluorine-containing resin emulsions, the particle size of the fluorine-containing resin is 0.10 μm to 0.40 μm, for example, 0.10 μm, 0.15 μm, 0.20 μm, 0.25 μm, 0.30 μm, 0.35 μm or 0.40 μm.

[0015] In this specification, the particle size of the fluorine-containing resin emulsion is measured by the laser diffraction method, and the measuring device is a Malvern laser particle size measuring device, model number MS3000. In this specification, the dielectric constant and dielectric loss are measured according to the split post dielectric resonator (SPDR) method, and the measurement conditions are state A and the frequency is 10 GHz.

[0016] Preferably, the inorganic fiber is any one or at least a combination of two selected from E glass fiber, NE glass fiber, L glass fiber, quartz fiber, alumina fiber, boron nitride fiber, silicon carbide fiber, zinc oxide fiber, magnesium oxide fiber, silicon nitride fiber, boron carbide fiber, aluminum nitride fiber, alumina whisker, boron nitride whisker, silicon carbide whisker, zinc oxide whisker, magnesium oxide whisker, silicon nitride whisker, boron carbide whisker or aluminum nitride whisker.

[0017] Preferably, the average diameter of the inorganic fiber is less than 13 micrometers, for example, 12 micrometers, 10 micrometers, 9 micrometers, 8 micrometers, 7 micrometers, 6 micrometers, 5 micrometers, 4 micrometers, 3 micrometers, 2 micrometers, 1 micrometer or 0.5 micrometer, etc., preferably less than 10 micrometers, and preferably 0.5 to 5 micrometers.

[0018] Preferably, the average length of the inorganic fiber is 1 to 100 millimeters, for example, 2 millimeters, 5 millimeters, 8 millimeters, 10 millimeters, 30 millimeters, 50 millimeters, 80 millimeters or 100 millimeters, and preferably 1 to 10 millimeters. The average diameter and average length of the inorganic fiber in the present invention are both obtained by observing and measuring with a scanning electron microscope.

[0019] Preferably, the adhesive can be manufactured by adding a solvent and dissolving and diluting it to an appropriate viscosity as needed, so that the fibers and the adhesive in the produced non-woven fabric can be uniformly dispersed. The solvent includes, for example, deionized water. The solvent will volatilize along with the oven drying and sintering in the manufacturing process of the non-woven fabric.

[0020] Preferably, the adhesive further includes a dispersant, a thickener, an antifoaming agent, etc. Preferably, the method for manufacturing the fluorine-containing resin adhesive nonwoven fabric involves mixing inorganic fibers and an adhesive, impregnating them, forming the mixture by papermaking, drying it in an oven, and sintering it to obtain the fluorine-containing resin adhesive nonwoven fabric.

[0021] Preferably, the impregnation time is 40 - 50 min, for example, 40 min, 43 min, 45 min, 48 min, or 50 min.

[0022] Preferably, the oven drying temperature is 120 - 150 °C, for example, 120 °C, 125 °C, 130 °C, 135 °C, 140 °C, 145 °C, or 150 °C, and the time is 1 - 30 min, for example, 1 min, 3 min, 5 min, 8 min, 10 min, 13 min, 15 min, 18 min, or 20 min.

[0023] Preferably, the sintering temperature is 250 °C - 350 °C, for example, 250 °C, 270 °C, 290 °C, 300 °C, 320 °C, 340 °C, or 350 °C, and the sintering time is 1 - 20 min, for example, 1 min, 3 min, 5 min, 8 min, 10 min, 13 min, 15 min, 18 min, or 20 min.

[0024] Preferably, the basis weight (also referred to as mass per unit area) of the fluorine-containing resin adhesive nonwoven fabric is 20 - 200 g / m², for example, 20 g / m², 25 g / m², 30 g / m², 35 g / m², 40 g / m², 50 g / m², 60 g / m², 80 g / m², 100 g / m², 120 g / m², 150 g / m², 180 g / m², or 200 g / m², and it is preferably 20 - 100 g / m². By adjusting the addition amounts of inorganic fibers, adhesive, solvent, and the vehicle speed, fluorine-containing resin adhesive nonwoven fabrics with different basis weights can be obtained.

[0025] Preferably, the inorganic filler includes any one or at least a combination of two or more of spherical titania, angular titania, spherical silica, hollow silica, barium titanate, strontium titanate, chopped glass fiber, alumina, boron nitride, silicon nitride, alumina whisker, boron nitride whisker, or hollow glass beads. The inorganic filler can be selected as needed. For example, a high-DK filler can be selected for a high-DK board material, and a thermal conductivity filler can be added to a thermal conductivity board material, and so on.

[0026] In the present invention, prepregs manufactured by combining a fluorine-containing resin emulsion with different fillers can meet different dielectric needs and thermal conductivity needs, for example, as follows.

[0027] The fluorine-containing resin composition contains, in parts by solid weight, 30 to 50 parts of a fluorine-containing resin, 25 to 35 parts of titania, and 10 to 20 parts of silica, and a circuit board with a Dk of 6 ± 0.5 can be manufactured using the same. Here, the fluorine-containing resin in parts by solid weight refers to the content of the fluorine-containing resin portion obtained by removing the solvent from the fluorine-containing resin emulsion, and can be obtained by multiplying the weight of the fluorine-containing resin emulsion by the solid content of the fluorine-containing resin emulsion.

[0028] The fluorine-containing resin composition contains, in parts by solid weight, 30 to 40 parts of a fluorine-containing resin, 55 to 70 parts of titania, and 5 to 20 parts of silica, and a circuit board with a Dk of 10 ± 0.5 can be manufactured using the same.

[0029] The fluorine-containing resin composition contains, in parts by solid weight, 30 to 60 parts of a fluorine-containing resin, 20 to 40 parts of boron nitride, 4 to 10 parts of titania, and 10 to 20 parts of silica, and a circuit board with a Dk of 3.5 ± 0.5 and a thermal conductivity exceeding 1.44 W / mk can be manufactured using the same.

[0030] The fluorine-containing resin composition contains, in parts by solid weight, 40 to 60 parts of a fluorine-containing resin, 0 to 10 parts of titania, and 40 to 60 parts of silica, and a circuit board with a Dk of 3 ± 0.5 can be manufactured using the same.

[0031] As a preferred technical solution of the present invention, the inorganic filler is a surface-modified inorganic filler. The copper-clad laminate obtained by performing surface modification using a reagent has better dielectric performance and a lower coefficient of thermal expansion.

[0032] Preferably, the surface modifier used for the surface modification is a silane coupling agent. Preferably, the silane coupling agent includes any one or at least a combination of two of a fluorine-containing silane coupling agent, an aminosilane coupling agent, an epoxysilane coupling agent, a vinylsilane coupling agent, or an acrylic silane coupling agent.

[0033] Preferably, based on 100% of the mass of the inorganic filler to be surface-treated, the dosage of the surface modifier is 0.05 to 0.5%, and may be, for example, 0.05%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, 0.5%, etc.

[0034] Exemplarily, the fluorine-containing resin composition is manufactured by a method including mixing a fluorine-containing resin emulsion and an inorganic filler and then uniformly dispersing them to obtain the fluorine-containing resin composition.

[0035] In the manufacturing process, a thickener, a dispersant, a solvent, etc. may be further added to the fluorine-containing resin composition. The addition amount is selected by those skilled in the art according to experience and process needs, and it is sufficient if the dipping, coating, and use of the fluorine-containing resin composition can be facilitated by obtaining an appropriate viscosity. In stages such as drying and sintering described later, auxiliary agents such as thickeners may partially or completely volatilize.

[0036] Preferably, the nonwoven prepreg is produced by immersing the fluorine-containing resin nonwoven fabric in the fluorine-containing resin composition, followed by drying and / or sintering.

[0037] Preferably, the drying temperature is 100 to 260 °C, and may be, for example, 110 °C, 130 °C, 150 °C, 170 °C, 190 °C, 200 °C, 210 °C, 230 °C or 250 °C.

[0038] Preferably, the drying time is 10 to 120 min, and may be, for example, 20 min, 30 min, 40 min, 50 min, 60 min, 70 min, 80 min, 90 min, 100 min or 110 min.

[0039] Preferably, the sintering temperature is 200 to 400 °C, and may be, for example, 210 °C, 230 °C, 250 °C, 270 °C, 290 °C, 300 °C, 310 °C, 330 °C, 350 °C, 370 °C or 390 °C.

[0040] Preferably, the sintering time is 0.1 to 12 h, and may be, for example, 0.2 h, 0.25 h, 0.5 h, 0.75 h, 1 h, 1.5 h, 2 h, 2.5 h, 3 h, 4 h, 5 h, 6 h, 7 h, 8 h, 9 h, 10 h or 11 h.

[0041] Preferably, the sintering is carried out in an inert gas atmosphere. Preferably, the inert gas atmosphere includes a nitrogen gas atmosphere and / or an argon gas atmosphere.

[0042] In another aspect, the present invention provides a metal foil-clad laminate including a metal foil and the above-described nonwoven prepreg.

[0043] Preferably, the metal foil is a copper foil. In this case, the metal foil-clad laminate is a copper-clad laminate.

[0044] As another aspect, the present invention provides a printed circuit board including at least one of the above-described nonwoven prepreg or metal foil laminate.

[0045] Preferably, the printed circuit board is a high-frequency printed circuit board. In the present invention, "high frequency" is defined as a frequency of 1 GHz or higher.

Advantages of the Invention

[0046] Compared with the prior art, the present invention has the following beneficial effects. The nonwoven prepreg according to the present invention is obtained by compounding a fluorine-containing resin composition with a fluorine-containing resin adhesive nonwoven fabric having a low dielectric loss. As a result, the nonwoven prepreg and the copper-clad laminate containing the same have excellent dielectric properties. At 10 GHz, the dielectric constant reaches 2.2 to 11, the dielectric loss is less than 0.003, and the copper-clad laminate further has a low coefficient of thermal expansion, so that the copper-clad laminate can meet the requirements for the performance of copper-clad laminate materials in the high-frequency communication field.

Embodiments for Carrying Out the Invention

[0047] Hereinafter, the technical solution of the present invention will be further described by specific embodiments. Those skilled in the art should understand that the above embodiments are only for understanding the present invention and should not be regarded as specifically limiting the present invention.

[0048] The experimental materials and apparatuses used in the examples and comparative examples of the present invention are as follows. (1) Fluorine-containing resin composition A-1: 64 parts by weight of polytetrafluoroethylene emulsion (PTFE emulsion, particle size 0.25 μm, solid content 55%, D210C manufactured by Daikin Industries, Ltd., Japan), 10 parts by weight of FEP resin emulsion (solid content 50 wt%, manufactured by Daikin Industries, Ltd., Japan, model number: ND-110), 3 parts of titania (average particle size 10 μm, purchased from WuXi Noble Electronics Co., Ltd., silane A171 surface treatment), and 60 parts of silica (average particle size 10 μm, purchased from JiangSu NOVORAY) are stirred and mixed for 2 h to obtain fluorine-containing resin composition A-1 resin.

[0049] Fluorine-containing resin composition A-2: 58.5 parts by weight of polytetrafluoroethylene emulsion (PTFE emulsion, particle size 0.25 μm, solid content 55%, D210C manufactured by Daikin Industries, Ltd., Japan), 32.5 parts of titania (average particle size 10 μm, purchased from WuXi Noble Electronics Co., Ltd.) and 17 parts of silica (average particle size 10 μm, purchased from JiangSu NOVORAY) are stirred and mixed for 2 h to obtain the fluorine-containing resin composition A-2 resin.

[0050] Fluorine-containing resin composition A-3: 55 parts by weight of polytetrafluoroethylene emulsion (PTFE emulsion, particle size 0.25 μm, solid content 55%, D210C manufactured by Daikin Industries, Ltd., Japan), 65 parts of titania (average particle size 10 μm, purchased from WuXi Noble Electronics Co., Ltd.) and 18.5 parts of silica (average particle size 10 μm, purchased from JiangSu NOVORAY, treated with silane KBM-503) are stirred and mixed for 2 h to obtain the fluorine-containing resin composition A-3 resin.

[0051] Fluorine-containing resin composition A-4: 60 parts by weight of polytetrafluoroethylene emulsion (PTFE emulsion, particle size 0.25 μm, solid content 55%, D210C manufactured by Daikin Industries, Ltd., Japan), 24 parts of boron nitride (average particle size 10 μm, purchased from AnHui Estone), 6 parts of titania (average particle size 10 μm, purchased from WuXi Noble Electronics Co., Ltd.) and 18 parts of silica (average particle size 10 μm, purchased from JiangSu NOVORAY, treated with silane KBM-12) are stirred and mixed for 2 h to obtain the fluorine-containing resin composition A-4 resin.

[0052] (2) The specific manufacturing method of the low dielectric loss non-woven fabric includes the following steps. The glass fiber and the fluorine-containing emulsion were immersed for 45 minutes and formed by papermaking. Then, after drying in an oven at 150 °C, it was sintered in a high-temperature oven environment at 320 °C for 10 minutes. After taking it out and cooling, low dielectric loss nonwoven fabrics with different unit weights were manufactured. The dosages of the glass fiber, the fluorine-containing emulsion, the adhesive, and the corresponding types of nonwoven fabrics are as follows.

[0053] Low dielectric loss nonwoven fabric B-1: E glass fiber with an average diameter of 8 μm (JUSHI China), FEP resin adhesive (solid content 50 wt%, manufactured by Daikin Industries, Ltd., Japan, model number: ND-110), the content of the adhesive is 10%, and the unit weight of the nonwoven fabric is 75 grams per square meter.

[0054] Low dielectric loss nonwoven fabric B-2: NE glass fiber with an average diameter of 5 μm (JUSHI China), PFA resin adhesive (solid content 55 wt%, manufactured by Daikin Industries, Ltd., Japan, model number: AD-2CR), the content of the adhesive is 20%, and the unit weight of the nonwoven fabric is 75 grams per square meter.

[0055] Low dielectric loss nonwoven fabric B-3: Quartz glass fiber with an average diameter of 0.5 μm and 5 μm (ShenJiu China), PTFE resin adhesive (solid content 55 wt%, manufactured by Daikin Industries, Ltd., Japan, model number: D210C), the content of the adhesive is 20%, and the unit weight of the nonwoven fabric is 25 grams per square meter.

[0056] (3) Other reinforcing materials General nonwoven fabric B-4: E glass fiber with an average diameter of 12 μm, epoxy resin adhesive, manufactured by Shaanxi Huatek, and the unit weight of the nonwoven fabric is 75 grams per square meter.

[0057] Nonwoven fabric B-5: It is different from low dielectric loss nonwoven fabric B-1 in that the content of the adhesive is 50%.

[0058] Nonwoven fabric B-6: It is manufactured from an acrylate adhesive and E glass fibers with an average diameter of 13 μm, produced by Shaanxi Huatek, and the basis weight of the nonwoven fabric is 75 grams per square meter. E glass cloth: E glass fibers, model number 106, manufactured by Asahi Schwebel Co., Ltd.

Example

[0059] (1) The fluorine-containing resin composition A-1 was impregnated into the nonwoven fabric B-1, dried in an oven at 100 °C for 1 h, sintered in an oven at 360 °C for 0.5 h, and a fluorine-containing resin nonwoven prepreg with a thickness of 380 μm was obtained.

[0060] (2) Two sheets of the fluorine-containing resin nonwoven prepreg were laminated, with a size of 250 mm × 250 mm. Copper foils with a thickness of 1 OZ were coated and laminated on the upper and lower surfaces of the laminated prepreg layer. The applied pressure was about 400 PSI, the maximum temperature was 380 °C, and the holding time was 90 min. After lamination, the copper-clad laminate was obtained.

Example

[0061] (1) The fluorine-containing resin composition A-1 was impregnated into the nonwoven fabric B-2, dried in an oven at 100 °C for 1 h, sintered in an oven at 360 °C for 0.5 h, and a fluorine-containing resin nonwoven prepreg with a thickness of 380 μm was obtained.

[0062] (2) Two sheets of the fluorine-containing resin nonwoven prepreg were laminated, with a size of 250 mm × 250 mm. Copper foils with a thickness of 1 OZ were coated and laminated on the upper and lower surfaces of the laminated resin layer. The applied pressure was about 400 PSI, the maximum temperature was 380 °C, and the holding time was 90 min. After lamination, the copper-clad laminate was obtained.

Example

[0063] (1) The fluorine-containing resin composition A-2 was impregnated into the nonwoven fabric B-3, dried in an oven at 100 °C for 1 h, sintered in an oven at 360 °C for 0.5 h, and a fluorine-containing resin nonwoven prepreg with a thickness of 127 μm was obtained.

[0064] (2) Stack two sheets of the fluorine-containing resin nonwoven prepreg, with a size of 250 mm × 250 mm, and laminate them with a 1 OZ copper foil coated on both the upper and lower surfaces of the laminated resin layer. The applied pressure is about 400 PSI, the maximum temperature is 380 °C, the holding time is 90 min, and laminate to obtain the copper-clad laminate.

Example

[0065] (1) Immerse nonwoven fabric B-3 in the fluorine-containing resin composition A-3, dry it in an oven at 100 °C for 1 h, and sinter it in an oven at 360 °C for 0.5 h to obtain a fluorine-containing resin nonwoven prepreg with a thickness of 127 μm.

[0066] (2) Stack two sheets of the fluorine-containing resin nonwoven prepreg, with a size of 250 mm × 250 mm, and laminate them with a 1 OZ copper foil coated on both the upper and lower surfaces of the laminated resin layer. The applied pressure is about 400 PSI, the maximum temperature is 380 °C, the holding time is 90 min, and laminate to obtain the copper-clad laminate.

Example

[0067] (1) Immerse nonwoven fabric B-3 in the fluorine-containing resin composition A-4, dry it in an oven at 100 °C for 1 h, and sinter it in an oven at 360 °C for 0.5 h to obtain a fluorine-containing resin nonwoven prepreg with a thickness of 127 μm.

[0068] (2) Stack two sheets of the fluorine-containing resin nonwoven prepreg, with a size of 250 mm × 250 mm, and laminate them with a 1 OZ copper foil coated on both the upper and lower surfaces of the laminated resin layer. The applied pressure is about 400 PSI, the maximum temperature is 380 °C, the holding time is 90 min, and laminate to obtain the copper-clad laminate.

[0069] [Comparative Example 1] (1) Immerse nonwoven fabric B-4 in the fluorine-containing resin composition A-1, dry it in an oven at 100 °C for 1 h, and sinter it in an oven at 360 °C for 0.5 h to obtain a fluorine-containing resin nonwoven prepreg with a thickness of 380 μm.

[0070] (2) Two pieces of the fluorine-containing resin nonwoven prepreg were laminated, with a size of 250 mm × 250 mm. Copper foils with a thickness of 1 OZ were coated and laminated on both the upper and lower surfaces of the laminated resin layer. The applied pressure was about 400 PSI, the maximum temperature was 380 °C, the holding time was 90 min, and lamination was carried out to obtain the copper-clad laminate.

[0071] [Comparative Example 2] (1) Nonwoven fabric B-5 was immersed in the fluorine-containing resin composition A-1, dried in an oven at 100 °C for 1 h, and sintered in an oven at 360 °C for 0.5 h to obtain a fluorine-containing resin nonwoven prepreg with a thickness of 380 μm.

[0072] (2) Two pieces of the fluorine-containing resin nonwoven prepreg were laminated, with a size of 250 mm × 250 mm. Copper foils with a thickness of 1 OZ were coated and laminated on both the upper and lower surfaces of the laminated resin layer. The applied pressure was about 400 PSI, the maximum temperature was 380 °C, the holding time was 90 min, and lamination was carried out to obtain the copper-clad laminate.

[0073] [Comparative Example 3] It is different from Example 1 only in that nonwoven fabric B-1 is replaced with nonwoven fabric B-6.

[0074] [Comparative Example 4] (1) 106-type E-glass cloth was immersed in the fluorine-containing resin composition A-1, dried in an oven at 100 °C for 1 h, and sintered in an oven at 360 °C for 0.5 h to obtain a fluorine-containing resin nonwoven prepreg with a thickness of 100 μm.

[0075] (2) Two pieces of the fluorine-containing resin nonwoven prepreg were laminated, with a size of 250 mm × 250 mm. Copper foils with a thickness of 1 OZ were coated and laminated on both the upper and lower surfaces of the laminated resin layer. The applied pressure was about 400 PSI, the maximum temperature was 380 °C, the holding time was 90 min, and lamination was carried out to obtain the copper-clad laminate.

[0076] [Comparative Example 5] (1) The non-woven fabric B-4 was immersed in the fluorine-containing resin composition A-2, dried in an oven at 100 °C for 1 h, and sintered in an oven at 360 °C for 0.5 h to obtain a fluorine-containing resin non-woven prepreg with a thickness of 127 μm.

[0077] (2) Two sheets of the fluorine-containing resin non-woven prepreg were laminated, with a size of 250 mm × 250 mm. Copper foils with a thickness of 1 OZ were coated and laminated on both the upper and lower surfaces of the laminated resin layer. The applied pressure was about 400 PSI, the maximum temperature was 380 °C, and the holding time was 90 min. After lamination, the copper-clad laminate was obtained.

[0078] Performance measurement The following performance measurements were carried out on the copper-clad laminates manufactured in the above-described examples and comparative examples.

[0079] (1) Measurement of Dk and Df: Measured according to the SPDR (split post dielectric resonator) method. The measurement conditions were in state A and the frequency was 10 GHz.

[0080] (2) Coefficient of thermal expansion (X / Y): Using IPC-TM-650 2.4.24, the coefficient of expansion change of the material in the X / Y directions and in the temperature range of -55 to 288 °C was measured.

[0081] The specific measurement results are shown in Table 1.

[0082]

Table 1

[0083] As can be seen from the above table, the non-woven prepreg according to the present invention, by immersing the fluorine-containing resin non-woven fabric in the fluorine-containing resin composition, enables the copper-clad laminate containing the non-woven prepreg to have excellent dielectric performance and a low coefficient of thermal expansion, and can meet the requirements for the performance of copper-clad laminate materials in the high-frequency communication field.

[0084] As can be seen from Examples 1 to 5, the copper-clad laminate containing the non-woven prepreg has a dielectric constant between 3.06 and 10.35, a dielectric loss of less than 0.003, and a coefficient of thermal expansion of less than 50 ppm. Both its dielectric loss and coefficient of thermal expansion are clearly superior to those of copper-clad laminates manufactured from general non-woven fabrics and glass fiber woven fabrics. And, as can be seen from Comparative Examples 1, 3, and 5, when using prepregs of general non-woven fabrics, the dielectric loss of the plate material improved slightly and the coefficient of thermal expansion increased. In Comparative Example 4, when using a prepreg of general E-glass cloth, the dielectric loss of the plate material became higher, and due to the braided structure of the glass cloth, the difference in the coefficient of thermal expansion in the X / Y directions became larger.

[0085] In Comparative Example 2, since the dosage of the fluorine-containing resin adhesive in the non-woven fabric was too high, the number of voids in the copper-clad laminate increased. Compared with Example 1, the dielectric constant of the plate material was slightly lower, but its dielectric loss was clearly higher and the coefficient of thermal expansion was higher.

[0086] In short, due to the prepreg of the fluorine-containing resin adhesive non-woven fabric according to the present invention, the copper-clad laminate containing the non-woven prepreg has excellent dielectric performance and properties such as a low coefficient of thermal expansion, and can be applied to the high-frequency communication field.

[0087] The applicant declares that the present invention has been described by the above examples for the non-woven prepreg, metal foil-clad laminate, and printed circuit board of the present invention, but the present invention is not limited to the above examples, that is, the present invention does not have to be implemented by the above examples. It is clear that any improvement to the present invention, equivalent substitution of each raw material of the product of the present invention, addition of auxiliary components, and selection of specific embodiments by those skilled in the art all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A nonwoven prepreg comprising a fluorine-containing resin adhesive nonwoven fabric and a fluorine-containing resin composition, wherein the fluorine-containing resin adhesive nonwoven fabric contains an adhesive which is a fluorine-containing resin emulsion and inorganic fibers, and the fluorine-containing resin composition contains 30 to 100 parts by weight of a fluorine-containing resin emulsion and 10 to 70 parts by weight of an inorganic filler, characterized in that it is a nonwoven prepreg.

2. The fluorine-containing resin emulsion is any one selected from a polytetrafluoroethylene emulsion, a polyperfluoroethylene propylene emulsion, a polyvinylidene fluoride emulsion, a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer emulsion, an ethylene-tetrafluoroethylene copolymer emulsion, a polychlorotrifluoroethylene emulsion, or an ethylene-chlorotrifluoroethylene copolymer emulsion, or a combination of at least two of them. Preferably, the weight percentage of the inorganic fibers in the fluorine-containing resin adhesive nonwoven fabric is 60 to 95%, and the weight percentage of the adhesive is 5% to 40%. Preferably, the solid content of the fluorine-containing resin emulsion is 30 to 70%. Preferably, the particle size of the fluorine-containing resin in the fluorine-containing resin emulsion is 0.10 μm to 0.40 μm. The nonwoven prepreg according to Claim 1, characterized in that.

3. The inorganic fibers are any one selected from E glass fibers, NE glass fibers, L glass fibers, quartz fibers, alumina fibers, boron nitride fibers, silicon carbide fibers, zinc oxide fibers, magnesium oxide fibers, silicon nitride fibers, boron carbide fibers, aluminum nitride fibers, alumina whiskers, boron nitride whiskers, silicon carbide whiskers, zinc oxide whiskers, magnesium oxide whiskers, silicon nitride whiskers, boron carbide whiskers, or aluminum nitride whiskers, or a combination of at least two of them. Preferably, the average diameter of the inorganic fibers is less than 13 micrometers, preferably less than 10 micrometers, and preferably 0.5 to 5 micrometers. Preferably, the average length of the inorganic fibers is 1 to 100 millimeters, preferably 1 to 10 millimeters. The nonwoven prepreg according to Claim 1 or 2, characterized in that.

4. The inorganic filler includes any one or at least a combination of two or more of spherical titania, angular titania, spherical silica, hollow silica, barium titanate, strontium titanate, chopped glass fiber, alumina, boron nitride, silicon nitride, alumina whisker, boron nitride whisker, or hollow glass beads. The nonwoven prepreg according to any one of claims 1 to 3, characterized in that.

5. The inorganic filler is a surface-modified inorganic filler. Preferably, the surface modifier used for the surface modification is a silane coupling agent. Preferably, the silane coupling agent includes any one or at least a combination of two or more of a fluorine-containing silane coupling agent, an aminosilane coupling agent, an epoxysilane coupling agent, a vinylsilane coupling agent, or an acrylic silane coupling agent. Preferably, based on 100% by mass of the inorganic filler to be surface-treated, the dosage of the surface modifier is 0.05 to 0.5%. Preferably, the adhesive further includes a defoaming agent in an amount of 0.01 to 1% by weight. Preferably, the fluorine-containing resin adhesive nonwoven fabric is a surface-treated nonwoven fabric. Preferably, the treating agent for the surface treatment is one or at least a mixture of two or more selected from a fluorine-containing silane coupling agent, an aminosilane coupling agent, an epoxysilane coupling agent, a vinylsilane coupling agent, an alkylsilane coupling agent, a borate coupling agent, a zirconate coupling agent, or a phosphate coupling agent. Preferably, the basis weight of the fluorine-containing resin adhesive nonwoven fabric is 20 to 200 g / m², and preferably 20 to 100 g / m². The nonwoven prepreg according to any one of claims 1 to 4, characterized in that.

6. The fluorine-containing resin composition includes 30 to 50 parts of a fluorine-containing resin, 25 to 35 parts of titania, and 10 to 20 parts of silica in parts by solid weight. Preferably, the fluorine-containing resin composition includes 30 to 40 parts of a fluorine-containing resin, 55 to 70 parts of titania, and 5 to 20 parts of silica in parts by solid weight. The nonwoven prepreg according to any one of claims 1 to 5, characterized in that.

7. The fluorine-containing resin composition contains, by solid weight parts, 30 to 60 parts of a fluorine-containing resin, 20 to 40 parts of boron nitride, 4 to 10 parts of titania, and 10 to 20 parts of silica, Preferably, the fluorine-containing resin composition contains, by solid weight parts, 40 to 60 parts of a fluorine-containing resin, 0 to 10 parts of titania, and 40 to 60 parts of silica. The nonwoven prepreg according to any one of claims 1 to 6, characterized in that.

8. The nonwoven prepreg is obtained by immersing the fluorine-containing resin adhesive nonwoven fabric in the fluorine-containing resin composition, drying, and sintering. The nonwoven prepreg according to any one of claims 1 to 7, characterized in that.

9. A metal foil laminate comprising a metal foil and the nonwoven prepreg according to any one of claims 1 to 8. Metal foil laminate.

10. A printed circuit board comprising at least one of the nonwoven prepreg or the metal foil laminate according to any one of claims 1 to 8. Printed circuit board.

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