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

Abstract

The invention discloses a lead-free medium-Tg CAF-resistant low-loss copper-clad plate material and a preparation process thereof, and belongs to the technical field of copper-clad plates. Aiming at the problems that the electrical property and the CAF resistance are influenced by large electron cloud density of bromine-containing substances and the electrical property of the material becomes poor due to aluminum hydroxide, bisphenol F type epoxy resin is adopted as main resin; the bromine-containing epoxy resin and the aluminum hydroxide are used in cooperation with the modified biphenyl epoxy resin, the methyl methacrylate-butadiene-styrene-maleic anhydride multipolymer, the fused silicon dioxide and the like, the use amount of the bromine-containing epoxy resin and the aluminum hydroxide is reduced, and finally the purposes of improving the CAF resistance of the material and reducing the dielectric loss of the material are 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 rapid development of electronic information technology, the performance and reliability of electronic products have become the focus of attention within and outside the industry. With the continuous advancement of integrated circuit technology, the trend of miniaturization and high-density integration of electronic components has become increasingly obvious, and the demand for high-performance and high-reliability electronic materials has also increased dramatically. As a basic material in the electronics industry, copper clad laminates are responsible for the conductivity, insulation and support of printed circuit boards. Their performance directly affects the overall performance and reliability of electronic products. In the context of increasingly stringent environmental protection laws, lead-free has become an important trend in the development of electronic materials.

[0003] CAF (Conductive Anodic Filament) resistance is an important indicator to measure 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 a conductive path, causing circuit failure or even short circuit, posing a serious threat to the stability and reliability of electronic products. Therefore, improved CAF resistance is of great significance to 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 under the action of an electric field, electrical energy is converted into other forms of energy due to the internal mechanism of the dielectric. The loss characteristics of copper clad laminates will directly affect the efficiency and quality of signal transmission. With the popularization of high-frequency and high-speed communication technologies, it is also particularly important to reduce the attenuation and interference during the signal transmission process of copper clad laminates.

[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 view of the problems raised in the background technology, the purpose of the present invention is to provide a lead-free medium Tg CAF-resistant, low-loss copper-clad laminate material and its preparation process. The present invention reduces the amount of traditional brominated epoxy resin, uses bisphenol F epoxy resin as the main resin, and combines various resins to construct an epoxy phenolic curing system, ultimately achieving the purpose of improving the CAF resistance of the material and reducing the dielectric loss of the material.

[0006] In order to achieve the above object, the present invention specifically adopts the following technical solutions: The present invention provides a preparation process of a lead-free medium Tg CAF-resistant and low-loss copper-clad laminate material, comprising the following steps: 1) Preparation of resin glue: add bisphenol F epoxy resin and brominated epoxy resin to the filler and shear at high speed at 30-60°C, then add modified biphenyl epoxy resin, phosphate flame retardant, methyl methacrylate-butadiene-styrene-maleic anhydride multipolymer and nitrogen-containing phenolic resin to the obtained mixture, and mature at constant temperature to obtain resin glue; 2) Preparation of prepreg: impregnating the glass fiber cloth with the resin glue obtained in step 1), and then baking at 170-210° C. to obtain a prepreg; 3) Pressing of copper clad laminate: 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 copper clad laminate material.

[0007] Furthermore, the filler in step 1) consists of fused silica, aluminum hydroxide and silicon carbide.

[0008] 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 8-10h; adding a curing agent to the obtained product, and curing at 150-200°C to obtain the polyphenyl ether modified biphenyl epoxy resin.

[0009] Furthermore, the molecular weight of the polyphenylene ether is 1800-2400, the catalyst is dibutyltin dilaurate, and the curing agent is diaminodiphenylmethane.

[0010] Furthermore, in step 1), the phosphate flame retardant is triphenyl phosphate.

[0011] Furthermore, the preparation method of the methyl methacrylate-butadiene-styrene-maleic anhydride multipolymer in step 1) is: adding an emulsifier to styrene-butadiene latex to form a stable emulsion system, then adding an initiator to the emulsion system in batches, and at the same time, mixing styrene, maleic anhydride and methyl methacrylate and slowly adding them to the emulsion, stirring and polymerizing, and finally breaking the emulsion to obtain the methyl methacrylate-butadiene-styrene-maleic anhydride multipolymer.

[0012] Furthermore, the emulsifier is sodium dodecylbenzene sulfonate, and the initiator is benzoyl peroxide.

[0013] 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.

[0014] Based on the excellent heat resistance and flame retardancy of brominated epoxy resin and aluminum hydroxide, most of the flame retardant systems of lead-free materials on the market are the combined effect of brominated epoxy resin and aluminum hydroxide. However, on the one hand, the density of the electron cloud in the chemical structure of brominated materials is relatively high due to the presence of bromine, so it has a greater impact on electrical properties. At the same time, too high an electron cloud density will also affect CAF resistance. On the other hand, aluminum hydroxide, as an inorganic flame retardant functional powder, will also cause the electrical properties of the material to deteriorate after being added to the glue system. Aiming at 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; and for 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 perform low dielectric modification on it. 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, not only the CAF resistance of the material is effectively improved, but also the heat resistance and flame retardancy of the material are guaranteed, the dielectric loss is reduced, and the use requirements of today's high-performance copper clad laminates can be met.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 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.

[0016] 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 in high-frequency and high-speed electronic fields. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical scheme and advantages of the present invention clearer, the technical scheme of the present invention will be clearly and completely described below in conjunction with the embodiments. If the specific conditions are not specified in the embodiments, they are carried out according to the conventional conditions or the conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments is not specified, they are all conventional products that can be purchased commercially.

[0018] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. 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" used herein includes any and all combinations of one or more related listed items.

[0019] Example 1 A preparation process of a lead-free medium Tg CAF-resistant and low-loss copper-clad laminate material, comprising: 1. Take polyphenylene ether (average molecular weight 2000) as the 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 h; add 8 parts of diaminodiphenylmethane to the obtained product, and cure (160°C for 2 h, 185°C for 1.5 h, 200°C for 1 h) to obtain polyphenylene ether modified biphenyl epoxy resin.

[0020] 2. Add an appropriate amount of sodium dodecylbenzene sulfonate to 100 parts of styrene-butadiene latex (styrene content 40%) with a solid content of 40%, mix evenly to form a stable emulsion system, then add 1 part of benzoyl peroxide to the emulsion system in multiple times, and 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, and finally demulsify and separate to obtain methyl methacrylate-butadiene-styrene-maleic anhydride multipolymer.

[0021] 3. Weigh 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 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 by weight.

[0022] 4. Add bisphenol F epoxy resin NPEL-170 and brominated epoxy resin NPEB-400 to the filler and high-speed shear for 15 min at 55°C and 500rpm, then add polyphenyl ether modified biphenyl epoxy resin, triphenyl phosphate, methyl methacrylate-butadiene-styrene-maleic anhydride copolymer, and nitrogen-containing phenolic resin PF8708 to the resulting mixture, and keep the constant temperature for aging for 12 h to obtain the resin adhesive; use the obtained resin adhesive to impregnate the glass fiber cloth, and then bake it at 200°C to obtain a semi-cured sheet with a resin content of 50%; take 8 adhesive sheets and overlap them with 2 copper foils (1oz) to press them into a copper clad laminate material with a thickness of 1.6 mm.

[0023] Example 2 A preparation process of a lead-free medium Tg CAF-resistant and low-loss copper-clad laminate material, comprising: 1. Take polyphenylene ether (average molecular weight 2200) as the 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 h; add 8 parts of diaminodiphenylmethane to the obtained product, and cure (160°C for 2 h, 185°C for 1.5 h, 200°C for 1 h) to obtain polyphenylene ether modified biphenyl epoxy resin.

[0024] 2. Add an appropriate amount of sodium dodecylbenzene sulfonate to 100 parts of styrene-butadiene latex (styrene content 40%) with a solid content of 40%, mix evenly to form a stable emulsion system, then add 1 part of benzoyl peroxide to the emulsion system in multiple times, and 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, and finally demulsify and separate to obtain methyl methacrylate-butadiene-styrene-maleic anhydride multipolymer.

[0025] 3. Weigh 20 parts of filler (12 parts of fused silica, 4 parts of aluminum hydroxide, 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 by weight.

[0026] 4. Add bisphenol F epoxy resin NPEL-170 and brominated epoxy resin NPEB-400 to the filler and high-speed shear for 15 min at 55°C and 500rpm, then add polyphenyl ether modified biphenyl epoxy resin, triphenyl phosphate, methyl methacrylate-butadiene-styrene-maleic anhydride copolymer, and nitrogen-containing phenolic resin PF8708 to the resulting mixture, and keep the constant temperature for aging for 12 h to obtain the resin adhesive; use the obtained resin adhesive to impregnate the glass fiber cloth, and then bake it at 200°C to obtain a semi-cured sheet with a resin content of 50%; take 8 adhesive sheets and overlap them with 2 copper foils (1oz) to press them into a copper clad laminate material with a thickness of 1.6 mm.

[0027] Example 3 A preparation process of a lead-free medium Tg CAF-resistant and low-loss copper-clad laminate material, comprising: 1. Take polyphenylene ether (average molecular weight 2000) as the 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 h; add 8 parts of diaminodiphenylmethane to the obtained product, and cure (160°C for 2 h, 185°C for 1.5 h, 200°C for 1 h) to obtain polyphenylene ether modified biphenyl epoxy resin.

[0028] 2. Add an appropriate amount of sodium dodecylbenzene sulfonate to 100 parts of styrene-butadiene latex (styrene content 40%) with a solid content of 40%, mix evenly to form a stable emulsion system, then add 1 part of benzoyl peroxide to the emulsion system in multiple times, and 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, and finally demulsify and separate to obtain methyl methacrylate-butadiene-styrene-maleic anhydride multipolymer.

[0029] 3. Weigh 28 parts of filler (14 parts of fused silica, 7 parts of aluminum hydroxide, 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 by weight.

[0030] 4. Add bisphenol F epoxy resin NPEL-170 and brominated epoxy resin NPEB-400 to the filler and high-speed shear for 15 min at 55°C and 500rpm, then add polyphenyl ether modified biphenyl epoxy resin, triphenyl phosphate, methyl methacrylate-butadiene-styrene-maleic anhydride copolymer, and nitrogen-containing phenolic resin PF8708 to the resulting mixture, and keep the constant temperature for aging for 12 h to obtain the resin adhesive; use the obtained resin adhesive to impregnate the glass fiber cloth, and then bake it at 200°C to obtain a semi-cured sheet with a resin content of 50%; take 8 adhesive sheets and overlap them with 2 copper foils (1oz) to press them into a copper clad laminate material with a thickness of 1.6 mm.

[0031] Comparative Example 1 Refer to the step parameters of Example 1, except that the amount of raw materials used in preparing the resin glue solution is adjusted to: 24 parts of filler (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 836 parts of nitrogen-containing phenolic resin PF870.

[0032] Comparative Example 2 The step parameters are as 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.

[0033] Comparative Example 3 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 type 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.

[0034] Test example The copper clad laminate samples prepared in the above embodiments and comparative examples were subjected to performance testing (testing standard IPC TM-650), and the results are shown in Table 1.

[0035] Table 1

[0036] In summary, the copper clad laminate material prepared by the present invention not only has a simple preparation method and is suitable for industrial production, but also has excellent Dk and Df values, good heat resistance and mechanical properties, and can meet the application requirements of high-frequency and high-speed electronic fields.

[0037] The embodiments described above only express several preferred embodiments of the present invention, and the descriptions thereof are relatively specific and detailed, but are not intended to limit the present invention. It should be noted that for those skilled in the art, the present invention may also have various changes and modifications, and any modifications, equivalent substitutions, improvements, etc. made within the concept and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A preparation process of a lead-free medium Tg CAF-resistant, low-loss copper-clad laminate material, characterized in that: The steps include: 1) Preparation of resin glue: add bisphenol F epoxy resin and brominated epoxy resin to the filler and shear at high speed at 30-60°C, then add modified biphenyl epoxy resin, phosphate flame retardant, methyl methacrylate-butadiene-styrene-maleic anhydride multipolymer and nitrogen-containing phenolic resin to the obtained mixture, and mature at constant temperature to obtain resin glue; 2) Preparation of prepreg: impregnating the glass fiber cloth with the resin glue obtained in step 1), and then baking at 170-210° C. to obtain a prepreg; 3) Pressing of copper clad laminate: 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 copper clad laminate material.

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

3. The preparation process of the lead-free medium Tg CAF-resistant and low-loss copper-clad laminate material according to claim 1, characterized in that: Step 1) The preparation method of the modified biphenyl epoxy resin is as follows: 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 h; adding a curing agent to the obtained product, and curing at 150-200° C. to obtain the polyphenyl 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 and low-loss copper-clad laminate material according to claim 1, characterized in that: Step 1) The phosphate flame retardant is triphenyl phosphate.

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

8. The preparation process of the lead-free medium Tg CAF-resistant and low-loss copper-clad laminate material according to claim 1, characterized in that: Step 1) The raw materials for preparing the resin glue solution 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.

9. 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 8.

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