Lead-free medium Tg CAF-resistant, low-loss copper-clad plate material and preparation process thereof

Abstract

The application discloses a lead-free medium-Tg CAF-resistant and low-loss copper-clad plate material and a preparation process thereof, and belongs to the technical field of copper-clad plates. In view of the problems that the electron cloud density of bromine-containing substances influences electrical properties and CAF resistance, and aluminum hydroxide also leads to poor electrical properties of the material, a bisphenol F type epoxy resin is used as a main resin, and a modified biphenyl epoxy resin, methyl methacrylate-butadiene-styrene-maleic anhydride multi-copolymer and fused silica are used in cooperation, so that the use amount of the bromine-containing epoxy resin and the aluminum hydroxide is reduced, and finally the purpose of improving the CAF resistance of the material and reducing the dielectric loss of the material is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of copper clad laminates, and in particular relates to a lead-free, medium-Tg, CAF-resistant, low-loss copper clad laminate material and a preparation process thereof. Background Art

[0002] In the era of rapidly developing electronic information technology, the performance and reliability of electronic products have become a focus of attention both within and outside the industry. With the continuous advancement of integrated circuit technology, the trend toward miniaturization and high-density integration of electronic components is becoming increasingly evident, and the demand for high-performance, high-reliability electronic materials is also increasing dramatically. Copper-clad laminates, as a fundamental material in the electronics industry, provide electrical conductivity, insulation, and support for printed circuit boards. Their performance directly impacts the overall performance and reliability of electronic products. Furthermore, amidst increasingly stringent environmental regulations, lead-free manufacturing has become a key trend in the development of electronic materials.

[0003] CAF (Conductive Anodic Filament) resistance is an important indicator for measuring the ability of electronic materials to resist electrochemical migration (ECM) under specific environmental conditions. Under high temperature, high humidity and other environments, electrochemical reactions may occur at the interface between metal materials and insulating materials, forming conductive pathways, leading to circuit failure and even short circuits, posing a serious threat to the stability and reliability of electronic products. Therefore, improved CAF resistance is of great significance for extending the service life of electronic products, ensuring long-term reliability, and reducing maintenance and replacement costs. Dielectric loss is the phenomenon that when a dielectric is subjected to an electric field, electrical energy is converted into other forms of energy due to the internal mechanism of the dielectric. The loss characteristics of the copper clad laminate will directly affect the efficiency and quality of signal transmission. With the popularization of high-frequency and high-speed communication technologies, it is particularly important to reduce the attenuation and interference during signal transmission of the copper clad laminate.

[0004] In view of this, in order to adapt to and meet the higher requirements of today's electronic components field, it is of great significance to develop high-performance, high-reliability lead-free, CAF-resistant, and low-loss copper clad laminate materials. Summary of the Invention

[0005] In response to the issues raised in the background art, the present invention aims to provide a lead-free, medium-Tg, CAF-resistant, low-loss copper-clad laminate material and its preparation process. This invention reduces the amount of traditional brominated epoxy resin used, using bisphenol F epoxy resin as the primary resin in combination with multiple resins to construct an epoxy novolac curing system, ultimately achieving the goals of improving the material's CAF resistance and reducing its dielectric loss.

[0006] To achieve the above object, the present invention specifically adopts the following technical solutions:

[0007] The present invention provides a preparation process of a lead-free, medium-Tg, CAF-resistant, low-loss copper-clad laminate material, comprising the following steps:

[0008] 1) Preparation of resin adhesive: bisphenol F epoxy resin and brominated epoxy resin are added to the filler and sheared at high speed at 30-60°C. Modified biphenyl epoxy resin, phosphate flame retardant, methyl methacrylate-butadiene-styrene-maleic anhydride multipolymer, and nitrogen-containing phenolic resin are then added to the resulting mixture and cured at a constant temperature to obtain the resin adhesive;

[0009] 2) Preparation of prepreg: impregnating glass fiber cloth with the resin solution obtained in step 1), followed by baking at 170-210°C to obtain a prepreg;

[0010] 3) Copper clad laminate pressing: Take a number of prepregs obtained in step 2) and combine them, apply copper foil on one or both sides, and press them together to obtain a copper clad laminate material.

[0011] Furthermore, the filler in step 1) consists of fused silica, aluminum hydroxide, and silicon carbide.

[0012] Furthermore, the preparation method of the modified biphenyl epoxy resin in step 1) is: using polyphenyl ether as a modifier, adding polyphenyl ether, polymethyltriethoxysilane and a catalyst to the biphenyl epoxy resin, and continuously stirring at 105-120°C for 8-10 hours; adding a curing agent to the resulting product, and curing at 150-200°C to obtain the polyphenyl ether modified biphenyl epoxy resin.

[0013] Furthermore, the molecular weight of the polyphenylene ether is 1800-2400, the catalyst is dibutyltin dilaurate, and the curing agent is diaminodiphenylmethane.

[0014] Furthermore, in step 1), the phosphate flame retardant is triphenyl phosphate.

[0015] Furthermore, the preparation method of the methyl methacrylate-butadiene-styrene-maleic anhydride multipolymer in step 1) is as follows: an emulsifier is added to styrene-butadiene latex to form a stable emulsion system, an initiator is then added to the emulsion system in batches, styrene, maleic anhydride and methyl methacrylate are mixed and then slowly added to the emulsion, stirred and polymerized, and finally demulsified and separated to obtain the methyl methacrylate-butadiene-styrene-maleic anhydride multipolymer.

[0016] Furthermore, the emulsifier is sodium dodecylbenzenesulfonate, and the initiator is benzoyl peroxide.

[0017] Furthermore, the raw materials for preparing the resin glue in step 1) include, by weight, 20-28 parts of filler, 40-55 parts of bisphenol F epoxy resin, 12-20 parts of brominated epoxy resin, 8-15 parts of modified biphenyl epoxy resin, 5-12 parts of phosphate flame retardant, 5-10 parts of methyl methacrylate-butadiene-styrene-maleic anhydride multipolymer, and 30-45 parts of nitrogen-containing phenolic resin.

[0018] Due to the excellent heat resistance and flame retardancy of bromine-containing epoxy resins and aluminum hydroxide, most lead-free flame retardant systems currently on the market use a combination of these two components. However, bromine-containing materials, due to the presence of bromine, have a high electron cloud density in their chemical structure, significantly affecting electrical properties. This high electron cloud density also affects CAF resistance. Furthermore, the addition of aluminum hydroxide, an inorganic flame retardant powder, to the adhesive system can also degrade the material's electrical properties. To address the defects of brominated epoxy resin, the present invention reduces the amount of brominated epoxy resin and uses bisphenol F epoxy resin as the main resin instead. To meet the requirements of CAF resistance and low loss performance, the present invention first selects biphenyl epoxy resin and bisphenol F epoxy resin, and uses polyphenylene ether to modify the epoxy resin to have a low dielectric constant. On this basis, the present invention also prepares a methyl methacrylate-butadiene-styrene-maleic anhydride tetrapolymer to construct a mixed resin system, and uses nitrogen-containing phenolic resin as a curing agent. Ultimately, the material's CAF resistance is effectively improved, while also ensuring the material's heat resistance and flame retardancy, reducing dielectric loss, and meeting the current demand for high-performance copper clad laminates.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. The process of the present invention reduces the amount of brominated epoxy resin and aluminum hydroxide, improves electrical properties while maintaining excellent heat resistance.

[0021] 2. The copper clad laminate material prepared by the present invention has good CAF resistance and low dielectric loss, and can meet the application requirements of high-frequency and high-speed electronic fields. DETAILED DESCRIPTION

[0022] To make the objects, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be described clearly and completely below in conjunction with the examples. Where specific conditions are not specified in the examples, the experiments were carried out under conventional conditions or the conditions recommended by the manufacturer. Where the manufacturer of the reagents or instruments is not specified, all are commercially available conventional products.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art in the art. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0024] Example 1

[0025] A preparation process for a lead-free, medium-Tg, CAF-resistant, low-loss copper-clad laminate material, comprising:

[0026] 1. Using polyphenylene ether (average molecular weight 2000) as a modifier, add 5 parts of polyphenylene ether, 6 parts of polymethyltriethoxysilane and 0.5 parts of dibutyltin dilaurate to 100 parts of biphenyl epoxy resin NC-3000, and stir continuously at 112°C for 10 hours. Add 8 parts of diaminodiphenylmethane to the resulting product, and cure (160°C for 2 hours, 185°C for 1.5 hours, and 200°C for 1 hour) to obtain polyphenylene ether modified biphenyl epoxy resin.

[0027] 2. Add an appropriate amount of sodium dodecylbenzenesulfonate to 100 parts of styrene-butadiene latex with a solid content of 40% (styrene content of 40%) and mix evenly to form a stable emulsion system. Subsequently, add 1 part of benzoyl peroxide to the emulsion system in multiple times. At the same time, mix 4 parts of styrene, 8 parts of maleic anhydride and 5 parts of methyl methacrylate and slowly add them to the emulsion. Stir and polymerize at a constant temperature of 60°C for 6 hours. Finally, demulsify and separate to obtain methyl methacrylate-butadiene-styrene-maleic anhydride copolymer.

[0028] 3. Weigh, by weight, 24 parts of filler (14 parts of fused silica, 5 parts of aluminum hydroxide, and 5 parts of silicon carbide), 48 parts of bisphenol F epoxy resin NPEL-170, 16 parts of brominated epoxy resin NPEB-400, 12 parts of the above-mentioned polyphenylene ether-modified biphenyl epoxy resin, 8 parts of triphenyl phosphate, 8 parts of the above-mentioned methyl methacrylate-butadiene-styrene-maleic anhydride multipolymer, and 36 parts of nitrogen-containing phenolic resin PF8708.

[0029] 4. Add bisphenol F epoxy resin NPEL-170 and brominated epoxy resin NPEB-400 to the filler and high-speed shear at 55°C and 500 rpm for 15 min. Then add polyphenylene ether modified biphenyl epoxy resin, triphenyl phosphate, methyl methacrylate-butadiene-styrene-maleic anhydride copolymer, and nitrogen-containing phenolic resin PF8708 to the resulting mixture, maintain constant temperature and mature for 12 h to obtain resin adhesive; use the obtained resin adhesive to impregnate glass fiber cloth, and then bake at 200°C to a resin content of 50% to obtain a semi-cured sheet; take 8 adhesive sheets and overlap with 2 pieces of copper foil (1oz) and press them into a copper clad laminate material with a thickness of 1.6 mm.

[0030] Example 2

[0031] A preparation process for a lead-free, medium-Tg, CAF-resistant, low-loss copper-clad laminate material, comprising:

[0032] 1. Using polyphenylene ether (average molecular weight 2200) as a modifier, add 5 parts of polyphenylene ether, 6 parts of polymethyltriethoxysilane and 0.5 parts of dibutyltin dilaurate to 100 parts of biphenyl epoxy resin NC-3000, and stir continuously at 120°C for 8 hours; add 8 parts of diaminodiphenylmethane to the resulting product, and cure (160°C for 2 hours, 185°C for 1.5 hours, and 200°C for 1 hour) to obtain polyphenylene ether modified biphenyl epoxy resin.

[0033] 2. Add an appropriate amount of sodium dodecylbenzenesulfonate to 100 parts of styrene-butadiene latex with a solid content of 40% (styrene content of 40%) and mix evenly to form a stable emulsion system. Subsequently, add 1 part of benzoyl peroxide to the emulsion system in multiple times. At the same time, mix 4 parts of styrene, 8 parts of maleic anhydride and 5 parts of methyl methacrylate and slowly add them to the emulsion. Stir and polymerize at a constant temperature of 60°C for 6 hours. Finally, demulsify and separate to obtain methyl methacrylate-butadiene-styrene-maleic anhydride copolymer.

[0034] 3. Weigh, by weight, 20 parts of filler (12 parts of fused silica, 4 parts of aluminum hydroxide, and 4 parts of silicon carbide), 42 parts of bisphenol F epoxy resin NPEL-170, 12 parts of brominated epoxy resin NPEB-400, 10 parts of the above-mentioned polyphenylene ether-modified biphenyl epoxy resin, 5 parts of triphenyl phosphate, 6 parts of the above-mentioned methyl methacrylate-butadiene-styrene-maleic anhydride multipolymer, and 32 parts of nitrogen-containing phenolic resin PF8708.

[0035] 4. Add bisphenol F epoxy resin NPEL-170 and brominated epoxy resin NPEB-400 to the filler and high-speed shear at 55°C and 500 rpm for 15 min. Then add polyphenylene ether modified biphenyl epoxy resin, triphenyl phosphate, methyl methacrylate-butadiene-styrene-maleic anhydride copolymer, and nitrogen-containing phenolic resin PF8708 to the resulting mixture, maintain constant temperature and mature for 12 h to obtain resin adhesive; use the obtained resin adhesive to impregnate glass fiber cloth, and then bake at 200°C to a resin content of 50% to obtain a semi-cured sheet; take 8 adhesive sheets and overlap with 2 pieces of copper foil (1oz) and press them into a copper clad laminate material with a thickness of 1.6 mm.

[0036] Example 3

[0037] A preparation process for a lead-free, medium-Tg, CAF-resistant, low-loss copper-clad laminate material, comprising:

[0038] 1. Using polyphenylene ether (average molecular weight 2000) as a modifier, add 5 parts of polyphenylene ether, 6 parts of polymethyltriethoxysilane and 0.5 parts of dibutyltin dilaurate to 100 parts of biphenyl epoxy resin NC-3000, and stir continuously at 110°C for 9 hours. Add 8 parts of diaminodiphenylmethane to the resulting product, and cure (160°C for 2 hours, 185°C for 1.5 hours, and 200°C for 1 hour) to obtain polyphenylene ether modified biphenyl epoxy resin.

[0039] 2. Add an appropriate amount of sodium dodecylbenzenesulfonate to 100 parts of styrene-butadiene latex with a solid content of 40% (styrene content of 40%) and mix evenly to form a stable emulsion system. Subsequently, add 1 part of benzoyl peroxide to the emulsion system in multiple times. At the same time, mix 4 parts of styrene, 8 parts of maleic anhydride and 5 parts of methyl methacrylate and slowly add them to the emulsion. Stir and polymerize at a constant temperature of 60°C for 6 hours. Finally, demulsify and separate to obtain methyl methacrylate-butadiene-styrene-maleic anhydride copolymer.

[0040] 3. Weigh, by weight, 28 parts of filler (14 parts of fused silica, 7 parts of aluminum hydroxide, and 7 parts of silicon carbide), 55 parts of bisphenol F epoxy resin NPEL-170, 18 parts of brominated epoxy resin NPEB-400, 15 parts of the above-mentioned polyphenylene ether-modified biphenyl epoxy resin, 10 parts of triphenyl phosphate, 5 parts of the above-mentioned methyl methacrylate-butadiene-styrene-maleic anhydride multipolymer, and 42 parts of nitrogen-containing phenolic resin PF8708.

[0041] 4. Add bisphenol F epoxy resin NPEL-170 and brominated epoxy resin NPEB-400 to the filler and high-speed shear at 55°C and 500 rpm for 15 min. Then add polyphenylene ether modified biphenyl epoxy resin, triphenyl phosphate, methyl methacrylate-butadiene-styrene-maleic anhydride copolymer, and nitrogen-containing phenolic resin PF8708 to the resulting mixture, maintain constant temperature and mature for 12 h to obtain resin adhesive; use the obtained resin adhesive to impregnate glass fiber cloth, and then bake at 200°C to a resin content of 50% to obtain a semi-cured sheet; take 8 adhesive sheets and overlap with 2 pieces of copper foil (1oz) and press them into a copper clad laminate material with a thickness of 1.6 mm.

[0042] Comparative Example 1

[0043] Refer to the step parameters of Example 1, except that the amount of raw materials used in preparing the resin glue is adjusted to:

[0044] 24 parts of fillers (5 parts of fused silica, 14 parts of aluminum hydroxide, 5 parts of silicon carbide), 48 parts of brominated epoxy resin NPEB-400, 16 parts of bisphenol F epoxy resin NPEL-170, 12 parts of the above-mentioned polyphenylene ether modified biphenyl epoxy resin, 8 parts of triphenyl phosphate, 8 parts of the above-mentioned methyl methacrylate-butadiene-styrene-maleic anhydride multipolymer, and 36 parts of nitrogen-containing phenolic resin PF870.

[0045] Comparative Example 2

[0046] The step parameters are as described in Example 1, except that the unmodified biphenyl epoxy resin NC-3000 is directly used to replace the polyphenylene ether modified biphenyl epoxy resin in step 3.

[0047] Comparative Example 3

[0048] Refer to the step parameters of Example 1, except that no multi-polymer is added, that is, the resin glue raw material composition is: 24 parts of filler (14 parts of fused silica, 5 parts of aluminum hydroxide, 5 parts of silicon carbide), 48 parts of bisphenol F epoxy resin NPEL-170, 16 parts of brominated epoxy resin NPEB-400, 12 parts of polyphenylene ether modified biphenyl epoxy resin, 8 parts of triphenyl phosphate, and 36 parts of nitrogen-containing phenolic resin PF8708.

[0049] Test example

[0050] The copper clad laminate samples prepared in the above examples and comparative examples were subjected to performance testing (testing standard IPC TM-650), and the results are shown in Table 1.

[0051] Table 1

[0052]

[0053] The prepared copper-clad plate material has simple preparation method, is suitable for industrial production, has excellent Dk and Df values, good heat resistance and mechanical properties, and can meet the application requirement of high-frequency and high-speed electronic field.

[0054] The above-described embodiments only express several preferred embodiments of the present application, which are described in detail and specifically, but are not used for limiting the present application. It should be pointed out that the present application can also have various changes and modifications for the person skilled in the art, any modification, equivalent replacement, improvement and the like within the concept and principle of the present application should be included in the protection scope of the present application.

Claims

1. A preparation process for a lead-free, medium-Tg, CAF-resistant, low-loss copper-clad laminate material, characterized in that: The steps include: 1) Preparation of resin adhesive: bisphenol F epoxy resin and brominated epoxy resin are added to the filler and sheared at high speed at 30-60°C. Modified biphenyl epoxy resin, phosphate flame retardant, methyl methacrylate-butadiene-styrene-maleic anhydride multipolymer, and nitrogen-containing phenolic resin are then added to the resulting mixture and cured at a constant temperature to obtain the resin adhesive; The raw materials for preparing the resin glue include, by weight, 20-28 parts of filler, 40-55 parts of bisphenol F epoxy resin, 12-20 parts of brominated epoxy resin, 8-15 parts of modified biphenyl epoxy resin, 5-12 parts of phosphate flame retardant, 5-10 parts of methyl methacrylate-butadiene-styrene-maleic anhydride multipolymer, and 30-45 parts of nitrogen-containing phenolic resin. 2) Preparation of prepreg: impregnating glass fiber cloth with the resin solution obtained in step 1), followed by baking at 170-210°C to obtain a prepreg; 3) Copper clad laminate pressing: Take a number of prepregs obtained in step 2) and combine them, apply copper foil on one or both sides, and press them together to obtain a copper clad laminate material.

2. The preparation process of the lead-free medium Tg CAF-resistant, low-loss copper-clad laminate material according to claim 1, characterized in that: Step 1) The filler consists of fused silica, aluminum hydroxide and silicon carbide.

3. The preparation process of the lead-free medium Tg CAF-resistant, low-loss copper-clad laminate material according to claim 1, characterized in that: Step 1) The modified biphenyl epoxy resin is prepared by adding polyphenylene ether, polymethyltriethoxysilane, and a catalyst to the biphenyl epoxy resin using polyphenylene ether as a modifier, and continuously stirring at 105-120° C. for 8-10 hours; adding a curing agent to the resulting product, and curing at 150-200° C. to obtain the polyphenylene ether modified biphenyl epoxy resin.

4. The preparation process of the lead-free medium Tg CAF-resistant, low-loss copper-clad laminate material according to claim 3, characterized in that: The molecular weight of the polyphenylene ether is 1800-2400, the catalyst is dibutyltin dilaurate, and the curing agent is diaminodiphenylmethane.

5. The preparation process of the lead-free medium Tg CAF-resistant, low-loss copper-clad laminate material according to claim 1, characterized in that: In step 1), the phosphate flame retardant is triphenyl phosphate.

6. The preparation process of the lead-free medium Tg CAF-resistant, low-loss copper-clad laminate material according to claim 1, characterized in that: Step 1) The preparation method of the methyl methacrylate-butadiene-styrene-maleic anhydride multipolymer is as follows: an emulsifier is added to styrene-butadiene latex to form a stable emulsion system, an initiator is then added to the emulsion system in batches, styrene, maleic anhydride and methyl methacrylate are mixed and then slowly added to the emulsion, stirred and polymerized, and finally demulsified and separated to obtain the methyl methacrylate-butadiene-styrene-maleic anhydride multipolymer.

7. The preparation process of the lead-free medium Tg CAF-resistant, low-loss copper-clad laminate material according to claim 6, characterized in that: The emulsifier is sodium dodecylbenzenesulfonate, and the initiator is benzoyl peroxide.

8. A lead-free, medium-Tg, CAF-resistant, low-loss copper-clad laminate obtained by the preparation process according to any one of claims 1 to 7.

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