Modified phosphorus-containing thermosetting resin composition, circuit board and application of modified phosphorus-containing thermosetting resin composition and circuit board

Abstract

The invention provides a modified phosphorus-containing thermosetting resin composition which is characterized by comprising the following components in parts by weight: modified phosphorus-containing epoxy resin and a resin composition. A circuit board prepared from the modified phosphorus-containing thermosetting resin composition has the characteristics of excellent flame retardance, heat resistance and mechanical property, low Dk and Df, and is suitable for manufacturing a high-frequency and high-speed printed circuit board (PCB).

Description

Technical Field

[0001] The invention belongs to the technical field of resins, and in particular relates to a modified phosphorus-containing thermosetting resin composition and a circuit board and use of the same as a flame retardant. Background Art

[0002] Flame retardancy is critical in printed circuit board (PCB) design. It can effectively slow the spread of flames, protect electronic devices from fire damage, and ensure that the circuit will not become a source of fire in the event of a malfunction or overload.

[0003] In addition, good flame retardancy also helps to comply with strict safety standards and protect electronic equipment. As electronic equipment develops towards high performance and miniaturization, the materials and processes of PCBs are also facing new challenges, especially their flame retardancy.

[0004] In the traditional PCB manufacturing process, halogen-containing flame retardants are often used to improve the flame retardancy of materials. However, these substances will release toxic and corrosive gases when burned, causing potential harm to the environment and human health. Therefore, stricter environmental regulations and increased environmental awareness have prompted the industry to find more environmentally friendly flame retardant solutions.

[0005] Currently, a popular alternative is to use phosphorus-containing resin compositions. Such flame retardants can form a protective layer at high temperatures, effectively slowing down the heat release rate of the material and reducing the risk of PCB combustion. At the same time, phosphorus-containing resin compositions can also increase the glass transition temperature of PCBs and enhance their stability in high temperature environments, thereby expanding the application range of PCBs in various electronic products. In addition, they also help reduce the water absorption rate of PCBs, reduce the damage caused by moisture to electronic components, and ensure the reliability and durability of electronic equipment in different environments.

[0006] However, the existing phosphorus-containing resin composition, such as that described in patent CN101137717A, has the defect of poor dielectric properties.

[0007] In view of this, the present invention is proposed. Summary of the invention

[0008] One of the objects of the present invention is to provide a modified phosphorus-containing thermosetting resin composition.

[0009] The second object of the present invention is to provide a copper-clad laminate material for a circuit board made using the modified phosphorus-containing thermosetting resin composition, wherein the copper-clad laminate material has excellent flame retardancy, heat resistance and mechanical properties, and is suitable for the production of high-frequency and high-speed printed circuit boards (PCBs).

[0010] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are particularly adopted:

[0011] The present invention provides a modified phosphorus-containing thermosetting resin composition, which comprises the following components in parts by weight:

[0012] A modified phosphorus-containing epoxy resin, wherein the modified phosphorus-containing epoxy resin is a biphenyl phenol epoxy resin represented by the following structural formula (I);

[0013]

[0014] The n is a positive integer ≥ 1, and the phosphorus content of the biphenyl phenol epoxy resin is 5% to 25%;

[0015] The resin composition comprises the following components by weight:

[0016] 50-100 parts of modified maleimide resin;

[0017] 50-150 parts of modified epoxy resin;

[0018] 50-100 parts of modified benzoxazine resin;

[0019] 80-200 parts of filling material;

[0020] 5-12 parts of toughening agent;

[0021] Initiator 0.2-3 parts;

[0022] The added mass ratio of the modified phosphorus-containing epoxy resin to the resin composition is in the range of 25 to 75 parts.

[0023] In a preferred embodiment of the present invention, the biphenyl phenol epoxy resin is a DOPO-modified biphenyl phenol epoxy resin having a structural formula as shown in formula (II),

[0024]

[0025] Wherein n is a positive integer ≥1, and the phosphorus content of the DOPO-modified biphenyl phenol epoxy resin is 5% to 25%.

[0026] In a preferred embodiment of the present invention, the modified maleimide resin is a bismaleimide resin as shown in the structure of formula (III):

[0027]

[0028] Wherein, R1 is selected from any one or a combination of two or more of the following structures:

[0029]

[0030] R2 is selected from any one or a combination of two or more of the following structures:

[0031]

[0032] The most preferred bismaleimide resin is shown in the following structural compound B1:

[0033]

[0034] In a preferred embodiment of the present invention, the modified maleimide resin is at least one or more of MDA-type bismaleimide resin, MED-type bismaleimide resin or biphenyl-type polymaleimide resin.

[0035] In a preferred embodiment of the present invention, the structure of the modified benzoxazine resin is shown in formula (IV):

[0036]

[0037] The R1 is O, Si, -CH2-, -CHCH3 or -C(CH3)2, and R2 / R3 is H, CH3, CH(CH3)2, C(CH3)3 or -Ph.

[0038] In a preferred embodiment of the present invention, the modified benzoxazine resin is at least one or more of BPA-type benzoxazine, BPF-type benzoxazine or ODA-type benzoxazine.

[0039] In a preferred embodiment of the present invention, the modified epoxy resin is biphenyl phenol epoxy resin.

[0040] In a preferred embodiment of the present invention, the filler material is at least one or more of silica, mica or talc, preferably spherical silica.

[0041] In a preferred embodiment of the present invention, the toughening agent is any one or more of polybutadiene, styrene-butadiene block copolymer, styrene-butadiene-styrene triblock copolymer, hydrogenated styrene / butadiene / styrene block copolymer, and maleic anhydride grafted styrene-butadiene-styrene block copolymer elastomer.

[0042] In a preferred embodiment of the present invention, the initiator is any one or more of azobisisobutyronitrile, azobis(2-isopropyl)butyronitrile, azobishexamethylenedicarbonitrile, dibenzoyl peroxide, dimethylbenzoyl peroxide, diisopropyl peroxide, diisopropylbenzene peroxide, cyclohexanone peroxide, methyl ethyl ketone peroxide, dicyclohexyl peroxide, benzoic acid peroxide, tert-butyl peroxide, butylbenzoic acid peroxide or tert-butylbenzoic acid peroxide.

[0043] In a preferred embodiment of the present invention, a solvent is further added to the modified phosphorus-containing thermosetting resin composition, and the modified phosphorus-containing thermosetting resin composition is dissolved by the solvent, and the solvent is any one or more of toluene, butanone, acetone, dimethylformamide, methyl ethyl ketone or propylene glycol methyl ether.

[0044] A method for preparing a copper-clad laminate having the modified phosphorus-containing thermosetting resin composition comprises the following steps:

[0045] The first step is to fully mix the solid components in the modified phosphorus-containing thermosetting resin composition and the solvent until the resin is completely dissolved to obtain a modified phosphorus-containing thermosetting resin composition;

[0046] The second step is to coat the modified phosphorus-containing thermosetting resin composition as an adhesive on the glass fiber cloth, and dry and cure it to volatilize the solvent to obtain a prepreg;

[0047] The third step is to overlap and press the prepreg obtained in step 2 with copper foil to obtain the copper clad laminate, and prepare the circuit board through the copper clad laminate.

[0048] The third object of the present invention is to provide a method for preparing the resin composition, comprising the following steps:

[0049] Step 1: fully mixing the resin, the combustion improver, the toughening agent, the filling material and the solvent until the resin is completely dissolved to obtain an adhesive;

[0050] Step 2: The adhesive obtained in step 1 is evenly coated on the glass fiber cloth by a glue coating machine, and dried and cured to volatilize the solvent to obtain a prepreg;

[0051] Step 3: The prepreg obtained in step 2 is overlapped with the copper foil and pressed to obtain the laminate.

[0052] In a preferred embodiment of the present invention, the line speed of the glue coating is 8-25m / min; the temperature of the drying and curing is 110-230°C; the pressing pressure is 70-600psi, the temperature is 70-240°C, the vacuum degree is 0.02-0.1MPa, the curing time is 50-130min, and the pressing time is 70-200min.

[0053] In a preferred embodiment of the present invention, the glass cloth-based copper-clad laminate can have various specifications and sizes, such as 36×48, 37×49, 40×48, 40.5×48.5, 41×49, 42.5×48.5, and 43×49.

[0054] In a preferred embodiment of the present invention, the glass fiber cloth is of grade E, with specifications of 1035, 1078, 1080, 2113, 2116 or 3313.

[0055] In a preferred embodiment of the present invention, the copper foil is 1 / 3oz, Hoz, 1oz, 2oz, 3oz, 4oz or RTF copper foil.

[0056] A use of a modified phosphorus-containing thermosetting resin composition, the use being for preparing a PCB circuit board.

[0057] The beneficial effects of the present invention are:

[0058] 1. The present invention adopts a modified phosphorus-containing thermosetting resin composition to improve the flame retardant properties of the material. Phosphorus elements promote the formation of a stable carbonized layer at high temperatures, which can effectively isolate oxygen and heat transfer, thereby delaying the combustion process of the material. At the same time, the addition of the phosphorus-containing flame retardant of the present invention not only enhances the stability of the material under extreme conditions, but also helps to reduce the release of harmful gases during combustion, meeting environmental protection requirements.

[0059] 2. The resin composition of the present invention adopts modified maleimide, modified phosphorus-containing epoxy resin and modified benzoxazine system to effectively improve the material properties. This combination optimizes the heat resistance, chemical resistance and mechanical strength of the resin. By introducing a reasonable proportion of modified maleimide, not only the glass transition temperature of the resin is increased, the thermal expansion coefficient is reduced, and the heat resistance is improved. In addition, the modified phosphorus-containing epoxy resin significantly improves the flame retardant properties of the copper clad laminate by introducing phosphorus. Compared with traditional halogen-containing flame-retardant epoxy resins, phosphorus-containing epoxy resins produce less smoke and harmful gases when burned, which is more environmentally friendly. DETAILED DESCRIPTION

[0060] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0061] A modified phosphorus-containing thermosetting resin composition is provided in the following examples.

[0062] The invention comprises (a) synthesis of DOPO-modified biphenyl phenol epoxy resin and (b) a resin composition, a prepreg and a metal-clad plate, wherein:

[0063] (a) The high activity of the PH bond in the DOPO molecule can be used to directly react with the epoxy group. At 120°C, 15% of a catalyst (triphenylphosphine) was added and reacted for 90 minutes. DOPO was grafted onto the epoxy resin chain to form an epoxy resin with flame retardant function. Through epoxy value titration and infrared spectroscopy research, it can be confirmed that the reaction degree of DOPO and epoxy resin is between 5% and 25%.

[0064] The biphenyl phenol epoxy resin used in the present invention is Guangdong Tongyu TER260K70.

[0065] The present invention provides a bismaleimide resin composition having the following structural formula:

[0066]

[0067] The components and trade names used in the present invention are shown in Table 1.

[0068] (b) The present invention will be further explained and illustrated by means of specific embodiments below:

[0069] 1. The specific preparation method of the resin composition of the present invention is as follows:

[0070] A. Add butanone and toluene into the reactor according to the formula in Table 1, turn on the high-speed stirrer at a speed of 1500 rpm, keep stirring continuously and control the tank temperature at 45°C;

[0071] B. Add different resins into the reaction kettle according to the formula in Table 1. After adding, continue stirring for 60 minutes until the resin is completely dissolved to obtain a resin composition.

[0072] 2. The preparation method of the resin glue of the present invention is as follows:

[0073] A. Add flame retardant and filler into the reactor according to the formula in Table 1, turn on the high-speed stirrer at a speed of 1800 rpm, and continue stirring for 60 minutes after the addition is completed;

[0074] B. Add initiator into the reactor according to the formula in Table 1. After adding, start the cooling water circulation and keep the speed at 1500rpm. Control the tank temperature at 45℃ and continue stirring for 180 minutes. The resin glue is ready.

[0075] 3. The method for preparing the prepreg of the present invention is as follows:

[0076] A. The gluing baking temperature is 140℃-160℃, and the gluing speed is 10m / min;

[0077] B. Use 2116E-glass fiberglass cloth;

[0078] C. The prepreg resin content is adjusted according to the required thickness of the metal foil-clad plate;

[0079] 4. The method for preparing the metal foil-clad plate of the present invention is as follows:

[0080] A. The number of prepreg sheets is determined according to the requirements of the metal foil laminated structure. Table 1 shows one of the laminated structures.

[0081] B. The metal foil used for the metal foil-clad board is selected as needed, and the RTF copper foil described in Table 1;

[0082] C. The lamination parameters of the metal foil clad plate are adjusted as required. The lamination conditions described in Table 1 are:

[0083] Vacuum pressure 50Torr; pressure 1.2-1.5MPa; hot plate temperature 150-220℃; curing time 200min.

[0084] The samples in Examples 1-6 and Comparative Examples 1-2 were tested for various properties according to the following methods:

[0085] (i) Glass transition temperature (Tg): The peak temperature of Tan δ was measured by a dynamic mechanical analysis (DMA) as the glass transition temperature.

[0086] (ii) Peel strength (PS): According to the standard of IPC-TM-650-2.4.8, the peel strength of the sample was tested using a universal tensile testing machine.

[0087] (III) 288°C heat resistance test (T288): A 8 mm × 8 mm copper foil substrate was placed on a thermal mechanical analyzer (TMA). The temperature was raised from room temperature to 288°C at a heating rate of 10°C / min and then maintained at 288°C. The dimensional changes of the sample were observed and the time of plate explosion after 288°C was recorded.

[0088] (iv) Thermal expansion coefficient: The thermal expansion coefficient of the sample shall be measured using a TMA instrument in accordance with the standards specified in IPC-TM-650 2.4.24;

[0089] (V) Dielectric constant (D k ) and dielectric loss factor (D f ): The dielectric constant and dielectric loss factor test methods are in accordance with the test specified in IPC-TM-650 2.5.5.9;

[0090] (VI) Flame retardancy: Sample test pieces with a size of 130 mm × 12.5 mm were taken and, according to the UL94 standard, 5 test pieces were subjected to 2 combustion tests respectively. The flame retardancy was evaluated by the sum of the duration of combustion during the combustion test;

[0091] (VII) Cracking temperature (Td): Select a square sample with a size of 6.35 mm × 6.35 mm and a minimum sample weight of 30 mg, bake it at 110 ± 2 °C for 24 hours, and cool it to room temperature in a desiccator. Use a thermogravimetric analyzer (TGA) to increase the temperature from room temperature to 450 °C at a rate of 10 °C / min. Record the percentage of weight loss of the sample as the temperature rises. The temperature at which the weight loss is 5% is reported as Td.

[0092] (VIII) PCT: The samples were subjected to a boiling test in a pressure cooker. The plates were boiled continuously for 120 min at 0.105 MPa and 120°C in a pressure cooker and then immersed in a 288°C tin furnace to observe the stratification and bubbling time. Samples with a stratification time of less than 5 min were evaluated as ×, and samples with a stratification time of more than 5 min and less than 10 min were evaluated as ○.

[0093] Table 1

[0094]

[0095]

[0096] From Table 1, it can be seen that the modified phosphorus-containing thermosetting resin composition used in the present invention improves the flame retardant properties of the material. The phosphorus element promotes the formation of a stable carbonized layer at high temperature. This carbonized layer can effectively isolate oxygen and heat transfer, thereby delaying the combustion process of the material. Therefore, compared with the comparative example, the flame retardant level is significantly improved.

[0097] The resin composition of the present invention adopts a modified maleimide, a modified phosphorus-containing epoxy resin and a modified benzoxazine system, which effectively improves material properties, and specifically optimizes the heat resistance, chemical resistance and mechanical strength of the resin compared with the comparative example.

[0098] By introducing a reasonable proportion of modified maleimide, not only the glass transition temperature of the resin is increased, the thermal expansion coefficient is reduced, and the heat resistance is improved. In addition, the modified phosphorus-containing epoxy resin significantly improves the flame retardant properties of the copper clad laminate by introducing phosphorus elements.

Claims

1. A modified phosphorus-containing thermosetting resin composition, characterized in that: Calculated by weight, it contains the following components: A modified phosphorus-containing epoxy resin, wherein the modified phosphorus-containing epoxy resin is a biphenyl phenol epoxy resin represented by the following structural formula (I); The n is a positive integer ≥ 1, and the phosphorus content of the biphenyl phenol epoxy resin is 5% to 25%; The resin composition comprises the following components by weight: 50-100 parts of modified maleimide resin; 50-150 parts of modified epoxy resin; 50-100 parts of modified benzoxazine resin; 80-200 parts of filling material; 5-12 parts of toughening agent; Initiator 0.2-3 parts; The modified phosphorus-containing epoxy resin is 25 to 75 parts of the resin composition.

2. A modified phosphorus-containing thermosetting resin composition according to claim 1, characterized in that: The biphenyl phenol epoxy resin is a DOPO-modified biphenyl phenol epoxy resin having a structural formula as shown in formula (II). Wherein n is a positive integer ≥1, and the phosphorus content of the DOPO-modified biphenyl phenol epoxy resin is 5% to 25%.

3. A modified phosphorus-containing thermosetting resin composition according to claim 1, characterized in that: The modified maleimide resin is a bismaleimide resin as shown in the structure of formula (III): Wherein, R1 is selected from any one or a combination of two or more of the following structures: R2 is selected from any one or a combination of two or more of the following structures:

4. A modified phosphorus-containing thermosetting resin composition according to claim 1, characterized in that: The structure of the modified benzoxazine resin is shown in formula (IV): Formula (IV), The R1 is O, Si, -CH2-, -CHCH3 or -C(CH3)2, and R2 / R3 is H, CH3, CH(CH3)2, C(CH3)3 or -Ph.

5. A modified phosphorus-containing thermosetting resin composition according to claim 1, characterized in that: The modified epoxy resin is biphenyl phenol epoxy resin.

6. A modified phosphorus-containing thermosetting resin composition according to claim 1, characterized in that: The filling material is at least one or more of silicon dioxide, mica or talc.

7. A modified phosphorus-containing thermosetting resin composition according to claim 1, characterized in that: The toughening agent is any one or more of polybutadiene, styrene-butadiene block copolymer, styrene-butadiene-styrene triblock copolymer, hydrogenated styrene / butadiene / styrene block copolymer, and maleic anhydride grafted styrene-butadiene-styrene block copolymer elastomer; The initiator is any one or more of azobisisobutyronitrile, azobis(2-isopropyl)butyronitrile, azobishexamethylenedicarbonitrile, dibenzoyl peroxide, dimethylbenzoyl peroxide, diisopropyl peroxide, diisopropylbenzene peroxide, cyclohexanone peroxide, methyl ethyl ketone peroxide, dicyclohexyl peroxide, benzoic acid peroxide, tert-butyl peroxide, butylbenzoic acid peroxide or tert-butylbenzoic acid peroxide.

8. A modified phosphorus-containing thermosetting resin composition according to claim 1, characterized in that: A solvent is also added to the modified phosphorus-containing thermosetting resin composition, and the modified phosphorus-containing thermosetting resin composition is dissolved by the solvent. The solvent is any one or more of toluene, butanone, acetone, dimethylformamide, methyl ethyl ketone or propylene glycol methyl ether.

9. A method for preparing a copper-clad laminate having the modified phosphorus-containing thermosetting resin composition according to any one of claims 1 to 8, characterized in that: The steps include: The first step is to fully mix the solid components in the modified phosphorus-containing thermosetting resin composition and the solvent until the resin is completely dissolved to obtain a modified phosphorus-containing thermosetting resin composition; The second step is to coat the modified phosphorus-containing thermosetting resin composition as an adhesive on the glass fiber cloth, and dry and cure it to volatilize the solvent to obtain a prepreg; The third step is to overlap and press the prepreg obtained in step 2 with copper foil to obtain the copper clad laminate, and prepare the circuit board through the copper clad laminate.

10. The use of the modified phosphorus-containing thermosetting resin composition according to any one of claims 1 to 8, characterized in that: The application is to prepare a PCB circuit board.

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