LOW DIELECTRIC LOSS NON-WOVEN FABRIC, PREPARATION METHOD THEREOF AND USE THEREOF

Abstract

Provided are a low dielectric loss non-woven fabric, a preparation method thereof and use thereof. The low dielectric loss non-woven fabric is composed of an inorganic fiber and a binder, and the binder is any one or a combination of at least two of a fluorine-containing resin emulsion, a polyolefin emulsion, a polyphenylene ether resin or a cyanate ester resin. The non-woven fabric of the present application has good dielectric properties and obvious strengthening effect, and can meet various performance requirements for copper clad laminate materials in the field of high-frequency communication.

Claims

1. A low dielectric loss non-woven fabric, wherein the low dielectric loss non-woven fabric is composed of an inorganic fiber and a binder, and the binder is any one or a combination of at least two of a fluorine-containing resin emulsion, a polyolefin emulsion, a polyphenylene ether resin or a cyanate ester resin.

2. The low dielectric loss non-woven fabric according to claim 1, wherein a weight percentage of the inorganic fiber is 60-95% in the low dielectric loss non-woven fabric, and a weight percentage of the binder is 5-40%.

3. The low dielectric loss non-woven fabric according to claim 1, wherein the binder is a fluorine-containing resin emulsion.

4. The low dielectric loss non-woven fabric according to claim 1, wherein the fluorine-containing resin emulsion is selected from any one or a combination of at least two of 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.

5. The low dielectric loss non-woven fabric according to claim 1, wherein, a solid content of the fluorine-containing resin emulsion is 30-70%.

6. The low dielectric loss non-woven fabric according to claim 1, wherein, a particle size of the fluorine-containing resin is 0.10-0.40 μm in the fluorine-containing resin emulsion.

7. The low dielectric loss non-woven fabric according to claim 1, wherein the polyolefin emulsion is selected from any one or a combination of at least two of an unsaturated polybutadiene resin emulsion, a styrene-butadiene-styrene triblock copolymer emulsion, a hydrogenated styrene-butadiene-styrene triblock copolymer emulsion or a styrene-butadiene resin emulsion.

8. The low dielectric loss non-woven fabric according to claim 1, a solid content of the polyolefin emulsion is 30-70%.

9. The low dielectric loss non-woven fabric according to claim 1, wherein the inorganic fiber is selected from any one or a combination of at least two of an E-glass fiber, an NE-glass fiber, an L-glass fiber or a quartz fiber.

10. The low dielectric loss non-woven fabric according to claim 1, wherein an average diameter of the inorganic fiber is less than 10 μm.

11. The low dielectric loss non-woven fabric according to claim 1, wherein an average length of the inorganic fiber is 1-100 mm.

12. The low dielectric loss non-woven fabric according to claim 1, wherein a mass per unit area of the low dielectric loss non-woven fabric is 20-200 g/m.sup.2, preferably 20-100 g/m.sup.2.

13. A preparation method of the low dielectric loss non-woven fabric according to claim 1, comprising the following steps: mixing an inorganic fiber with a binder, impregnating the fiber, subjecting them to papermaking molding, and drying them, so as to obtain the low dielectric loss non-woven fabric.

14. A prepreg, comprising the low dielectric loss non-woven fabric according to claim 1 and a resin composition adhered thereto by impregnation.

15. The prepreg according to claim 14, the resin composition is a fluorine-containing resin emulsion.

16. The prepreg according to claim 14, the fluorine-containing resin emulsion is selected from any one or a combination of at least two of 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.

17. A copper clad laminate, comprising a copper foil and the prepreg according to claim 14.

18. A printed circuit board, comprising a copper foil and the prepreg according to claim 14.

Description

DETAILED DESCRIPTION

[0035] The technical solutions of the present application are further described below through specific embodiments. It should be apparent to those skilled in the art that the embodiments are merely used for a better understanding of the present application, and should not be regarded as a specific limitation to the present application.

[0036] Raw materials used in the following examples and comparative examples are as follows:

[0037] Fluorinated ethylene propylene (FEP) resin emulsion, with a particle size of 0.20 μm, with a solid content of 50 wt %, from Japan Daikin Industries, Ltd., Brand: ND-110.

[0038] Perfluoroalkoxy (PFA) resin emulsion, with a particle size of 0.20 μm, with a solid content of 55 wt %, from Japan Daikin Industries, Ltd., Brand: AD-2CR.

[0039] PTFE resin emulsion, with a particle size of 0.25 μm, with a solid content of 55 wt %, from Japan Daikin Industries, Ltd., Brand: D210C.

[0040] Polyolefin emulsion, with a particle size of 0.1 μm, with a solid content of 45 wt %, a sample from Beijing Yanshan Petrochemical Company.

[0041] Polyphenylene ether binder: 100 parts of vinyl-modified polyphenylene ether (Mitsubishi Gas Chemical OPE-2ST) were weighted out, dissolved in a solvent of toluene, and stirred uniformly to obtain a polyphenylene ether binder.

[0042] Low-CTE (coefficient of thermal expansion) resin A: 450 g of the PTFE resin emulsion was taken, stirred and mixed at a high speed for 2 h to obtain a uniform resin composition.

[0043] Thermosetting resin A: 30 parts by weight of ethylene-propylene rubber (with a number average molecular mass of 80000 g/mol, from America Lion Chemical Corporation), 40 parts by weight of polybutadiene (with a molecular mass of 3200 g/mol, from Nippon Soda Co., Ltd.), and 2 parts by weight of benzoyl peroxide (from Shanghai Kang Lang Biological Technology Co., Ltd.) were dissolved in 50 parts by weight of xylene and mixed uniformly, so as to obtain a uniform resin composition.

[0044] Thermosetting resin B: 70 parts by weight of methyl methacrylate-terminated polyphenylene ether resin (MMA-PPE) (SA9000, from SABIC) were mixed with 70 parts by weight of toluene that was used as a solvent, and dissolved completely to obtain a functionalized polyphenylene ether resin solution, then 30 parts by weight of styrene-butadiene copolymer R100 (from Sartomer company) were added as a cross-linking curing agent, 3 parts by weight of dicumyl peroxide (DCP) were added as an initiator, and 15 parts by weight of ethylene bis(tetrabromophthalimide) BT-93 W (from Albemarle Corporation, with a bromine content of 67.2%) were added as a brominated flame retardant, and the above mixture was mixed in toluene, and stirred and dissolved to obtain a uniform resin composition.

[0045] E-glass fiber with an average diameter of 5 μm, from China Jushi Co., Ltd.

[0046] NE-glass fiber with an average diameter of 5 μm, from China Jushi Co., Ltd.

[0047] Quartz fibers with average diameters of 1 μm and 5 μm, from China Shenjiu.

[0048] E-glass fiber with an average diameter of 8 μm, from China Jushi Co., Ltd.

[0049] Non-woven fabric, prepared from an epoxy binder and an E-glass fiber with an average diameter of 13 μm, from Shaanxi Huatek.

[0050] Non-woven fabric, prepared from an acrylate binder and an E-glass fiber with an average diameter of 13 μm, from Shaanxi Huatek.

[0051] Non-woven fabric, prepared from a melamine binder and an E-glass fiber with an average diameter of 13 μm, from Shaanxi Huatek.

Example 1

[0052] In this example, a low dielectric loss non-woven fabric is provided, and the low dielectric loss non-woven fabric is composed of a glass fiber and a binder, and the binder is a FEP emulsion.

[0053] A specific preparation method includes the following steps:

[0054] 92 parts by weight of the E-glass fiber (with the average diameter of 5 μm) were impregnated with 8 parts by weight of the FEP binder for 45 min, subjected to papermaking molding, then dried in an oven at 150° C., then sintered in a high temperature oven at 300° C. for 30 min, and taken out and cooled to obtain a non-woven fabric A with a mass per unit area of 20 g/m.sup.2.

Example 2

[0055] 85 parts by weight of the NE-glass fiber (with the average diameter of 5 μm) were impregnated with 15 parts by weight of the FEP binder for 45 min, subjected to papermaking molding, then dried in an oven at 150° C., then sintered in a high temperature oven at 300° C. for 30 min, and taken out and cooled to obtain a non-woven fabric B with a mass per unit area of 75 g/m.sup.2.

Example 3

[0056] 70 parts by weight of the quartz fibers (with the average diameters of 1 μm and 5 μm, at a mass ratio of 1:4) were impregnated with 30 parts by weight of the FEP binder for 45 min, subjected to papermaking molding, then dried in an oven at 140° C., then sintered in a high temperature oven at 220° C. for 28 min, and taken out and cooled to obtain a non-woven fabric C with a mass per unit area of 75 g/m.sup.2.

Example 4

[0057] 85 parts by weight of the E-glass fiber (with the average diameter of 8 μm) were impregnated with 15 parts by weight of the PFA binder for 45 min, subjected to papermaking molding, then dried in an oven at 140° C., then sintered in a high temperature oven at 350° C. for 28 min, and taken out and cooled to obtain a non-woven fabric D with a mass per unit area of 75 g/m.sup.2.

Example 5

[0058] 85 parts by weight of the E-glass fiber (with the average diameter of 8 μm) were impregnated with 15 parts by weight of the polyolefin binder for 45 min, subjected to papermaking molding, then dried in an oven at 120° C., and taken out and cooled to obtain a non-woven fabric E with a mass per unit area of 120 g/m.sup.2.

Example 6

[0059] 85 parts by weight of the E-glass fiber (with the average diameter of 8 μm) were impregnated with 15 parts by weight of the vinyl-modified polyphenylene ether (Mitsubishi Gas Chemical OPE-2ST) binder for 45 min, subjected to papermaking molding, then dried in an oven at 200° C., and taken out and cooled to obtain a non-woven fabric F with a mass per unit area of 120 g/m.sup.2.

[0060] The main materials and parameters of the non-woven fabrics in the above examples are summarized in Table 1.

TABLE-US-00001 TABLE 1 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Non-woven fabric A B C D E F number Binder type FEP FEP FEP PFA polyolefin PPO Binder amount, 8 15 30 15 15  15  wt % Glass fiber type E-glass NE-glass Quartz E-glass E-glass E-glass fiber fiber fiber fiber fiber fiber Glass fiber 5  5 1 + 5  8 8 8 diameter, μm Mass per unit area 20  75 75 75 120  120  of the non-woven fabric, g/m.sup.2

Example 7

[0061] In this example, a PTFE copper clad laminate is provided, and a preparation method specifically includes the steps below.

[0062] Step (1): the non-woven fabric A of Example 1 was impregnated with the low-CTE resin A by an sizing glue machine, so as to obtain a prepreg H with a sized resin content of 90%.

[0063] Step (2): the prepreg H obtained in step (1) was placed into a vacuum oven, baked at 100° C. for 1 h to remove moisture, then baked at 260° C. for 1 h to remove additives, and then baked at 350° C. for 10 min to obtain a bonding sheet with a thickness of 0.25 mm.

[0064] Step (3): one single bonding sheet was covered with copper foils of 1 OZ thickness on the upper and lower sides and subjected to lamination, in which a pressure applied was 400 PSI, and a maximum temperature and a retention time were 380° C./60 min, so as to obtain the PTFE copper clad laminate.

Example 8

[0065] This example differs from Example 7 only in that the non-woven fabric A in step (1) was replaced with the non-woven fabric B to obtain a prepreg I.

Example 9

[0066] This example differs from Example 7 only in that the non-woven fabric A in step (1) was replaced with the non-woven fabric C to obtain a prepreg J.

Example 10

[0067] This example differs from Example 7 only in that the non-woven fabric A in step (1) was replaced with the non-woven fabric D to obtain a prepreg K.

Example 11

[0068] In this example, a high-frequency circuit substrate is provided, and a preparation method specifically includes the steps below.

[0069] Step (1): the non-woven fabric E of Example 5 was impregnated with the thermosetting resin A by an sizing glue machine, so as to obtain a prepreg M with a sized resin content of 90%.

[0070] Step (2): the prepreg M obtained in step (1) was placed into an oven at 100° C., baked for 1 h to remove solvent, so as to obtain a bonding sheet.

[0071] Step (3): resin layers of one single bonding sheet were covered with copper foils of 1 OZ thickness on the upper and lower sides for stacking arrangement, and put into a press for curing to obtain the high-frequency circuit substrate, in which the curing had a temperature of 200° C., a time of 90 min, and a pressure of 50 kg/cm.sup.2.

Example 12

[0072] In this example, a high-frequency circuit substrate is provided, and a preparation method specifically includes the steps below.

[0073] Step (1): the non-woven fabric F of Example 6 was impregnated with the thermosetting resin B by an sizing glue machine, so as to obtain a prepreg N with a sized resin content of 90%.

[0074] Step (2): the prepreg N obtained in step (1) was dried in an oven at 100° C. to remove the solvent toluene, so as to obtain a bonding sheet.

[0075] Step (3): resin layers of one single bonding sheet were arranged with copper foils of 1 OZ thickness on the upper and lower sides, and laminated and cured under vacuum in a press for 90 min, in which a curing pressure was 50 kg/cm.sup.2 and a curing temperature is 200° C., so as to obtain the high-frequency circuit substrate.

Comparative Example 1

[0076] This comparative example differs from Example 7 only in that the non-woven fabric A in step (1) was replaced with the non-woven fabric with epoxy binder, and others were exactly the same.

Comparative Example 2

[0077] This comparative example differs from Example 7 only in that the non-woven fabric A in step (1) was replaced with the non-woven fabric with acrylate binder, and others were exactly the same.

Comparative Example 3

[0078] This comparative example differs from Example 7 only in that the non-woven fabric A in step (1) was replaced with the non-woven fabric with melamine binder, and others were exactly the same.

Comparative Example 4

[0079] This comparative example differs from Example 11 only in that the non-woven fabric E in step (1) was replaced with the non-woven fabric with epoxy binder, and others were exactly the same.

Comparative Example 5

[0080] This comparative example differs from Example 12 only in that the non-woven fabric F in step (1) was replaced with the non-woven fabric with epoxy binder, and others were exactly the same.

Comparative Example 6

[0081] This comparative example differs from Example 7 only in that the binder was excessive in the non-woven fabric A in step (1), and a ratio was 50%, and others were exactly the same.

[0082] Performance evaluation was performed on the copper clad laminates or high-frequency circuit substrates of Examples 7-12 and Comparative Examples 1-6, and the methods are described below.

[0083] 1. Dk and Df: SPDR (split post dielectric resonator) method was used to test, a test condition was A state and a frequency was 10 GHz.

[0084] 2. Peel strength: according to the method from GB/T 4722-2017 7.2.

[0085] The test results are shown in Table 2 and Table 3.

TABLE-US-00002 TABLE 2 Examples 7-12 Indicator 7 8 9 10 11 12 Dk (10 GHz) 2.26 2.23 2.25 2.20 2.70 2.52 Df (10 GHz) 0.0012 0.0013 0.0010 0.0012 0.0035 0.0025 Peel Strength 1.4 1.3 1.6 1.5 0.8 0.8 (N/mm)

TABLE-US-00003 TABLE 3 Comparative Examples 1-6 Indicator 1 2 3 4 5 6 Dk (10 GHz) 2.28 2.29 2.30 2.75 2.55 2.33 Df (10 GHz) 0.0031 0.0035 0.0041 0.0055 0.0042 0.0028 Peel Strength 0.6 0.6 0.6 0.5 0.5 0.5 (N/mm)

[0086] What can be seen from Table 2 and Table 3 is as follows.

[0087] It can be seen that for the copper clad laminates in Examples 7-10 which are prepared by mixing PTFE and the non-woven fabrics prepared with low-loss binders, the dielectric loss (Dk (10 GHz) is lower than 2.26, and Df (10 GHz) is lower than 0.0013) and the peel strength (more than or equal to 1.3 N/mm) are obviously better than the performance of copper clad laminates in Comparative Examples 1-3 which are prepared with the common non-woven fabrics.

[0088] It can be seen that for the copper clad laminate in Examples 11 which is prepared by the hydrocarbon system and the non-woven fabric prepared with low-loss binder, the dielectric loss and the peel strength are obviously better than the performance of copper clad laminate in Comparative Example 4 which is prepared with the common non-woven fabric.

[0089] It can be seen that for the copper clad laminate in Examples 12 which is prepared by the polyphenylene ether system and the non-woven fabric prepared with low-loss binder, the dielectric loss and the peel strength are obviously better than the performance of copper clad laminate in Comparative Example 5 which is prepared with the common non-woven fabric.

[0090] The low-loss binder used in Comparative Example 6 is excessive, resulting in excessively high dielectric loss of the board.

[0091] The applicant has stated that although the low dielectric loss non-woven fabric, the preparation method thereof and the use thereof in the present application are described by the above embodiments, the present application is not limited to the above embodiments, which means that the present application does not necessarily rely on the above embodiments to be implemented. It should be apparent to those skilled in the art that any improvement of the present application, the equivalent replacement of various raw materials of the product in the present application, the addition of auxiliary components, the selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present application.