Resin glue solution for copper-clad plate, high-heat-resistant copper-clad plate and preparation method thereof

Abstract

The application provides a resin glue solution for copper-clad plates, a high-heat-resistant copper-clad plate and a preparation method, and relates to the technical field of copper-clad plates.The resin glue solution for copper-clad plates provided by the application takes ordinary epoxy resin and isocyanate-modified epoxy resin as a base material, and adopts organic micro-powder polyether sulfone PES powder with good heat resistance performance.Compared with inorganic micro-powder, the organic micro-powder polyether sulfone PES powder has more excellent dispersing performance.Further, a higher proportion of the organic micro-powder polyether sulfone PES powder is adopted, and is matched with eight amino-phenyl-POSS.Eight amino-phenyl-POSS matching not only promotes the dispersion of the organic micro-powder polyether sulfone PES powder, but also enables the amino in the eight amino-phenyl-POSS to directly react with the epoxy resin, thereby further improving the heat resistance of the epoxy resin.Eight amino-phenyl-POSS containing silicon elements and multiple amino groups is adopted to better improve the peeling strength, toughness and water resistance of the resin glue solution, and further improve the comprehensive performance of the obtained copper-clad plate.

Description

Technical Field

[0001] This invention relates to the field of copper clad laminate technology, and particularly to a resin adhesive for copper clad laminates, a high heat-resistant copper clad laminate, and a preparation method thereof. Background Technology

[0002] Copper clad laminate, also known as copper-clad laminate, is widely used in fields such as computers, mobile communications, etc.

[0003] Since 2006, the industry has entered the era of lead-free soldering, which has led to an increase in soldering temperature, and therefore the requirements for the heat resistance of copper-clad laminates have also increased accordingly.

[0004] Epoxy resins possess excellent physical, mechanical, and electrical insulation properties, and are widely used in coatings, adhesives, and other fields. They are also frequently used as the base resin for copper-clad laminates (CCLs). Common CCL manufacturing methods often employ brominated epoxy resins; however, brominated epoxy resins have a low glass transition temperature, which cannot meet the high soldering temperature requirements when using lead-free soldering. Multifunctional epoxy resins can improve the heat resistance of CCLs, meeting the requirements of lead-free soldering. Therefore, it is particularly important to develop a CCL with high heat resistance, low cost, and a simple manufacturing process.

[0005] Due to the implementation of the EU RoHS directive, the global electronics industry has long since entered the era of lead-free soldering. In lead-free soldering, the melting point of the solder used is 30-40°C higher than that of lead-based solder, and the soldering time above the melting point is also about 50 seconds longer. Therefore, the heat received by the board material during soldering is significantly increased, requiring copper-clad laminates to have better heat resistance. Traditional FR-4 copper-clad laminates have a glass transition temperature of only around 130°C and a thermal decomposition temperature of only 300-310°C, resulting in relatively low heat resistance. While they can be used in general electronic products, they are unsuitable for high-density interconnects and integrated circuits. With the rapid development and constant updates in electronic products, printed circuits are required to become thinner and more multilayered. This necessitates substrate materials with higher glass transition temperatures, heat resistance, and low expansion rates, while ensuring that other properties are not compromised to improve the reliability of interconnects and mounting.

[0006] Chinese patent application CN107245221B discloses a lead-free, high-heat-resistant copper-clad laminate production adhesive, mainly...

[0007] The raw materials include: 30-60 parts of low-bromine epoxy resin, 10-30 parts of high-bromine epoxy resin, 5-10 parts of tetrafunctional epoxy resin, 20-40 parts of 4-(N-maleimide)phenol glycidyl ether, 2.5-4 parts of dicyandiamide, 0.05-0.2 parts of curing accelerator, 20-50 parts of inorganic filler, and 0.5-2 parts of silane coupling agent KH560. The 4-(N-maleimide)phenol glycidyl ether is synthesized from maleic anhydride, p-bromoaniline, and glycidol. The FR-4 copper-clad laminate prepared by this invention exhibits excellent comprehensive performance, meeting the requirements of high-end PCBs. However, this invention uses a relatively large amount of inorganic filler. Inorganic fillers are difficult to disperse, easily causing an increase in adhesive viscosity, processing difficulties, poor matrix mechanical strength and toughness, and reduced adhesion. Summary of the Invention

[0008] In order to improve the mechanical strength, toughness, adhesion and heat resistance of the adhesive matrix for heat-resistant copper clad laminates in the prior art, this application provides a resin adhesive for copper clad laminates, a high heat-resistant copper clad laminate and a preparation method thereof.

[0009] In a first aspect, this application provides a resin adhesive for copper-clad laminates:

[0010] A resin adhesive for copper-clad laminates, comprising the following components by weight:

[0011] 40-120 parts epoxy resin; 40-80 parts isocyanate modified epoxy resin; 30-60 parts polyethersulfone (PES) powder; 20-40 parts octa-aminophenyl-POSS; 8-20 parts curing agent; 0.1-2 parts curing accelerator; 50-120 parts acetone; wherein the curing agent is one or more of polyether polyol, aromatic amine curing agent, and acid anhydride curing agent, and the curing accelerator is one or more of tertiary amine accelerator, thiazole accelerator, and metal catalyst.

[0012] Furthermore, the curing agent is a composition of polyether polyol and aromatic amine curing agent in a ratio of (1-3):1.

[0013] Furthermore, the polyether polyol is a composition of polyether diol, polyether triol, and polyether tetraol in a mass ratio of 1:(1-4):1; the molecular weight of the polyether diol is 400-1000; the molecular weight of the polyether triol is 1000-6000; and the molecular weight of the polyether tetraol is 200-800.

[0014] Furthermore, the surface of the polyethersulfone (PES) powder is coated with a silane coupling agent, which is an amino-containing silane coupling agent and / or an epoxy-containing silane coupling agent.

[0015] Furthermore, the particle size of the polyethersulfone (PES) powder is 1-20 micrometers.

[0016] Furthermore, the amino-containing silane coupling agent includes one of 3-aminopropyltriethoxysilane, N-(2-amino-ethyl)-3-aminopropanetriethoxysilane, 3-aminopropanetrimethoxysilane, and N-(2-amino-ethyl)-3-aminopropanetrimethoxysilane.

[0017] Furthermore, the epoxy resin is one or more of bisphenol F type epoxy resin and bisphenol A type epoxy resin; the thiazole accelerator is one or more of imidazole, 2-methylimidazolium, 1-benzylphenyl-2-ethylimidazolium, 2-phenylimidazolium, 2-ethyl-4-methylimidazolium, 1-aminoethyl-2-methylimidazolium, and 1-cyanoethylimidazolium; the aromatic amine curing agent includes one or more of diaminodiphenyl sulfone, diaminodiphenylmethane, m-phenylenediamine, and diethyltoluenediamine; and the acid anhydride curing agent includes one or more of phthalic anhydride, trimellitic anhydride, tung oil anhydride, and methylhexahydrophthalic anhydride.

[0018] Secondly, this application provides a method for preparing a resin adhesive for copper-clad laminates, which includes the following steps:

[0019] Epoxy resin and isocyanate-modified epoxy resin are mixed evenly, acetone is added and stirred, then polyethersulfone (PES) powder, octa-aminophenyl-POSS, curing agent and curing accelerator are added to the mixture and stirred at 25-40℃ to obtain the resin solution for copper clad laminate.

[0020] The polyethersulfone (PES) powder is mixed with a silane coupling agent, ball-milled for modification, sieved, and then used in a resin adhesive for copper plates.

[0021] Thirdly, this application provides a method for preparing a copper-clad laminate, comprising the following steps:

[0022] Impregnate fiberglass cloth with the resin solution of this application or the resin solution obtained by the preparation method described in this application, and dry it at 100-180℃ for 10-30 minutes to obtain a semi-cured sheet; take several semi-cured sheets, stack them together, cut them, cover both sides with copper foil, and hot press them at 190-230℃ for 80-240 minutes to obtain a high heat-resistant copper-clad laminate.

[0023] Fourthly, this application provides a copper-clad laminate comprising the resin adhesive described in this application or the resin adhesive obtained by the preparation method described in this application.

[0024] Beneficial Effects: 1. The resin adhesive for copper-clad laminates in this application uses ordinary epoxy resin and isocyanate-modified epoxy resin as base materials, and adds organic micronized polyethersulfone (PES) powder with good heat resistance. Compared with inorganic micronized powder, organic micronized PES powder has superior dispersibility. Furthermore, a higher proportion of organic micronized PES powder is used in combination with octa-aminophenyl-POSS. The combination with octa-aminophenyl-POSS not only promotes the dispersion of organic micronized PES powder, but also allows the amino groups in the octa-aminophenyl group to react directly with the epoxy resin, further improving the heat resistance of the epoxy resin. The use of octa-aminophenyl-POSS containing silicon and multiple amino groups effectively improves the peel strength, toughness, and water resistance of the resin adhesive, thereby improving the overall performance of the obtained copper-clad laminate.

[0025] 2. The curing agent in this application is a combination of polyether polyol and aromatic amine curing agent. The polyether polyol is a combination of polyether diol, polyether triol, and polyether tetraol, and the dosage is preferred. The use of polyether polyol effectively promotes the dispersion of polyether sulfone (PES) powder, resulting in a cured sheet with appropriate crosslinking degree, which improves the toughness, adhesion, mechanical properties, and heat resistance of the cured sheet formed by the adhesive. The aromatic amine curing agent improves the heat resistance of the cured sheet, and the polyether polyol overcomes the defects of poor toughness and adhesion when using only aromatic amine curing agent, resulting in copper-clad laminate with high comprehensive performance.

[0026] 3. The surface modification of polyethersulfone (PES) powder with silane coupling agent improves its dispersion performance, adhesive properties, adhesion properties, and mechanical properties; further optimization of aminosilane coupling agent further enhances the overall performance of the obtained copper-clad laminate. Detailed Implementation

[0027] To make the technical solution of the present invention clearer, the present invention will be further described in detail below with reference to specific embodiments.

[0028] Example 1: A method for preparing a high heat-resistant copper-clad laminate, using raw materials as shown in Table 1, and including the following preparation steps:

[0029] 1) Preparation of polyethersulfone (PES) powder modified with silane coupling agent: KH-550 and ethanol were mixed at a ratio of 1:9, and 0.1% acetic acid was added to adjust the pH to 5. The mixture was magnetically stirred at 25 °C for 30 minutes. Then, the hydrolyzed silane solution was sprayed onto the PES powder under stirring at 200 rpm. The mixture was allowed to stand for 1 hour to allow the silane to be adsorbed. Next, zirconia balls and pretreated PES powder were loaded at a ball-to-powder ratio of 5:1. The ball milling speed was set to 300 rpm. The mixture was ball-milled for 4 hours, and the undispersed agglomerates were removed through a 400-mesh sieve to obtain polyethersulfone (PES) powder modified with silane coupling agent.

[0030] 2) Preparation of resin solution for copper clad laminate: Weigh the raw materials according to the formula, mix the epoxy resin and isocyanate modified epoxy resin evenly, then add acetone, and stir at 60 °C for 2 h to obtain a mixture; then add polyethersulfone (PES) powder, octa-aminophenyl-POSS, curing agent and curing accelerator to the mixture, and stir at 30 °C for 1.5 h to obtain the resin solution for copper clad laminate.

[0031] 3) Preparation of high heat-resistant copper clad laminate:

[0032] The resin solution obtained in step 2) is impregnated with E-type glass fiber cloth for 12 minutes and then dried at 140°C for 25 minutes to obtain a semi-cured sheet.

[0033] The prepregs are stacked together, cut, and covered with copper foil on both sides. They are then hot-pressed to obtain a high heat-resistant copper-clad laminate. The hot-pressing process involves a pressure of 350 PSI, a temperature of 200℃, and a time of 100 min.

[0034] Examples 2 and 3 describe a method for preparing a high heat-resistant copper-clad laminate, which differs from Example 1 in that the weight and type of raw materials used are different, as detailed in Table 1.

[0035] Table 1. List of raw materials and their weights used in the preparation methods of Examples 1 to 3.

[0036]

[0037] Example 4, a method for preparing a high heat-resistant copper-clad laminate, differs from Example 1 in that the mass ratio of polypropylene oxide diol to diaminodiphenyl sulfone in the curing agent is 3:1.

[0038] Example 5, a method for preparing a high heat-resistant copper-clad laminate, differs from Example 1 in that the mass ratio of polypropylene oxide diol to diaminodiphenyl sulfone in the curing agent is 1:3.

[0039] Example 6, a method for preparing a high heat-resistant copper-clad laminate, differs from Example 1 in that, in the curing agent, a composition of polypropylene oxide diol (molecular weight 600) and polyether triol N310 (molecular weight 3000) in a mass ratio of 1:1 is used to replace polypropylene oxide diol (molecular weight 600) in equal amounts.

[0040] Example 7, a method for preparing a high heat-resistant copper-clad laminate, differs from Example 1 in that, in the curing agent, a composition of polypropylene oxide diol (molecular weight 600) and pentaerythritol-based polyether (molecular weight 400) in a mass ratio of 1:1 is used to replace polypropylene oxide diol (molecular weight 600) in equal amounts.

[0041] Example 8, a method for preparing a high heat-resistant copper-clad laminate, differs from Example 1 in that, in the curing agent, a composition of polypropylene oxide diol (molecular weight 600), polyether triol N310 (molecular weight 3000), and pentaerythritol-based polyether (molecular weight 400) in a mass ratio of 1:1:1 is used to replace polypropylene oxide diol (molecular weight 600) in equal amounts.

[0042] Example 9, a method for preparing a high heat-resistant copper-clad laminate, differs from Example 1 in that, in the curing agent, a composition of polypropylene oxide diol (molecular weight 600), polyether triol N310 (molecular weight 3000), and pentaerythritol-based polyether (molecular weight 400) in a mass ratio of 1:4:1 is used to replace polypropylene oxide diol (molecular weight 600) in equal amounts.

[0043] Example 10, a method for preparing a high heat-resistant copper-clad laminate, differs from Example 1 in that, in the curing agent, a composition of polypropylene oxide diol (molecular weight 600), polyether triol N310 (molecular weight 3000), and pentaerythritol-based polyether (molecular weight 400) in a mass ratio of 1:5:1 is used to replace polypropylene oxide diol (molecular weight 600) in equal amounts.

[0044] Example 11, a method for preparing a high heat-resistant copper-clad laminate, differs from Example 1 in that, in the curing agent, diaminodiphenyl sulfone is used to replace polypropylene oxide diol (molecular weight 600) in an equal amount.

[0045] Example 12, a method for preparing a high heat-resistant copper-clad laminate, differs from Example 1 in that the curing agent used is trimellitic anhydride.

[0046] Example 13, a method for preparing a high heat-resistant copper-clad laminate, differs from Example 1 in that, in the curing agent, γ-glycidyloxypropyltrimethoxysilane is used in an equal amount to replace 3-aminopropyltriethoxysilane in step 1).

[0047] Example 14, a method for preparing a high heat-resistant copper-clad laminate, differs from Example 1 in that, in step 1), polyethersulfone (PES) powder (particle size 10 μm) is used to replace the modified polyethersulfone (PES) powder in an equal amount.

[0048] Comparative Example 1, a method for preparing a high heat-resistant copper-clad laminate, differs from Example 1 in that an octa-epoxy cage-type silsesquioxane is used to replace octa-aminophenyl-POSS in an equal amount.

[0049] Comparative Example 2, a method for preparing a high heat-resistant copper-clad laminate, differs from Example 1 in that methyl phenyl silicone resin is used to replace octa-aminophenyl-POSS in an equal amount.

[0050] Comparative Example 3, a method for preparing a high heat-resistant copper-clad laminate, differs from Example 1 in that it does not use octa-aminophenyl-POSS.

[0051] Performance testing results are shown in Table 1:

[0052] 1. Glass transition temperature Tg: The Tg of the adhesive used in copper clad laminates was tested in accordance with GB / T 40396-2021.

[0053] 2. Water absorption rate: The test was conducted in accordance with GB / T1462-2005. The copper-clad laminate was immersed in a constant temperature water bath at 25℃ for 24 hours, and the mass change before and after immersion was measured to determine the water absorption rate of the copper-clad laminate.

[0054] 3. Peel strength: The copper-clad laminate was tested in accordance with GB / T 4722-2017.

[0055] 4. Bending strength: The copper-clad laminate was tested in accordance with GB / T 2567-2021. The bending strength specimen size was 4.0 mm thick, 100 mm long and 15 mm wide. The test speed was 10 mm / min, the number of specimens was 5, the test temperature was 23℃, the relative humidity was 50%, and the specimen conditioning time was 30 h.

[0056] 5. PCT: Steam in a 121℃ 105KPa pressure cooker for 1 hour, immerse in a 288℃ tin furnace, and record the time of board delamination.

[0057] Table 1. Performance list of resin solutions and copper-clad laminates obtained by the preparation methods of Examples 1 to 14 and Comparative Examples 1 to 3.

[0058]

[0059] The experimental data from Examples 1 and 4 are superior to those from Example 5, indicating that the preferred curing agent is a combination of polyether polyol and aromatic amine curing agent in a 1:3:1 ratio, which simultaneously improves heat resistance, peel strength, flexural strength, and PCT performance. The combination of polyether polyol and aromatic amine curing agent exhibits good compatibility. The use of polyether polyol improves the dispersion performance of modified polyethersulfone PES powder / polyethersulfone PES powder, while also enhancing the flexibility, adhesion, and heat resistance of the cured adhesive; the aromatic amine curing agent improves heat resistance.

[0060] The overall experimental data of Examples 8 and 9 are superior to those of Examples 6 and 7, and the overall experimental data of Examples 6 and 7 are superior to those of Examples 6 and 7, indicating that Examples 1 and 4 are superior. This shows that using a composition of polyether polyol and aromatic amine curing agent as a curing agent, and using a composition of resin liquids of polyether diol, polyether triol, and polyether tetraol as a polyol, further improves the peel strength, flexural strength, PCT performance, water resistance, and heat resistance of the resin liquid. Using polyols with different molecular weights and different numbers of functional groups as curing agents results in cured sheets with moderate crosslinking degree, high adhesion performance, and flexibility.

[0061] The overall experimental data of Examples 8 and 9 are better than those of Example 10. The possible reason is that Example 10 uses a larger amount of polyether triol N310 (molecular weight 3000) with a higher molecular weight, which reduces the amount of small molecule curing agent, resulting in a decrease in the crosslinking degree and adhesion performance of the cured sheet.

[0062] The experimental data on Tg, peel strength, flexural strength, and PCT of Example 1, as well as Examples 11 and 12, show that the curing agent, composed of polyether polyol and aromatic amine curing agent, works synergistically with other components in the adhesive to improve the overall performance of the copper-clad laminate. This may be because the use of polyether polyol effectively promotes the dispersion of polyethersulfone (PES) powder, while also ensuring that the cured sheet formed by the adhesive has an appropriate degree of crosslinking, thus improving toughness, adhesion, mechanical properties, and heat resistance.

[0063] The overall performance of Example 1 is superior to that of Examples 13 and 14, indicating that surface modification of the polyethersulfone (PES) powder with a silane coupling agent improves its dispersion, adhesive, adhesion, and mechanical properties. Further optimization with an aminosilane coupling agent further enhances the overall performance. This may be because the amino groups on the surface of the modified PES powder can directly react with the epoxy groups in the epoxy resin, thus better modifying the epoxy resin.

[0064] The overall performance of Example 1 is superior to that of Comparative Examples 1 to 3, indicating that the use of octa-aminophenyl-POSS in the adhesive solution in combination with other raw materials can improve the overall performance of the copper-clad laminate. This may be because, compared to octa-epoxy cage-type silsesquioxanes, octa-aminophenyl-POSS can directly react with the epoxy groups in the epoxy resin, thus better modifying the epoxy resin; compared to epoxy groups, octa-aminophenyl-POSS and the modified polyethersulfone (PES) powder contain the same polar amino groups on their surface, exhibiting better affinity and promoting better dispersion of the modified PES powder; without the use of octa-aminophenyl-POSS in the adhesive solution, the water resistance, toughness, and adhesion of the cured sheet decrease.

[0065] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A resin adhesive for copper-clad laminates, characterized in that, By weight, it includes the following components: 40-120 parts epoxy resin; 40-80 parts of isocyanate-modified epoxy resin; 30-60 parts of polyethersulfone (PES) powder; 20-40 parts of octaaminophenyl-POSS; 8-20 parts of curing agent; Curing accelerator 0.1-2 parts; 50-120 parts acetone; The curing agent is one or more of polyether polyols and aromatic amine curing agents, and the curing accelerator is one or more of tertiary amine accelerators, thiazole accelerators, and metal catalysts. The curing agent is a composition of polyether polyol and aromatic amine curing agent in a mass ratio of (1-3):

1.

2. The resin adhesive for copper-clad laminates according to claim 1, characterized in that, The polyether polyol is a composition of polyether diol, polyether triol, and polyether tetraol in a mass ratio of 1:(1-4):1; the molecular weight of the polyether diol is 400-1000; the molecular weight of the polyether triol is 1000-6000; and the molecular weight of the polyether tetraol is 200-800.

3. The resin adhesive for copper-clad laminates according to claim 1, characterized in that, The surface of the polyethersulfone (PES) powder is coated with a silane coupling agent, which is an amino-containing silane coupling agent and / or an epoxy-containing silane coupling agent.

4. The resin adhesive for copper-clad laminates according to claim 3, characterized in that, The amino-containing silane coupling agent includes one of 3-aminopropyltriethoxysilane, N-(2-amino-ethyl)-3-aminopropanetriethoxysilane, 3-aminopropanetrimethoxysilane, and N-(2-amino-ethyl)-3-aminopropanetrimethoxysilane.

5. The resin adhesive for copper-clad laminates according to claim 1, characterized in that, The epoxy resin is one or more of bisphenol F type epoxy resin and bisphenol A type epoxy resin; the thiazole accelerator is one or more of imidazole, 2-methylimidazolium, 1-benzylphenyl-2-ethylimidazolium, 2-phenylimidazolium, 2-ethyl-4-methylimidazolium, 1-aminoethyl-2-methylimidazolium, and 1-cyanoethylimidazolium; the aromatic amine curing agent includes one or more of diaminodiphenyl sulfone, diaminodiphenylmethane, m-phenylenediamine, and diethyltoluenediamine.

6. The method for preparing the resin solution for copper-clad laminates according to claim 1, characterized in that, Includes the following steps: Epoxy resin and isocyanate-modified epoxy resin are mixed evenly, acetone is added and stirred, then polyethersulfone (PES) powder, octa-aminophenyl-POSS, curing agent and curing accelerator are added to the mixture and stirred at 25-40℃ to obtain the resin solution for copper clad laminate.

7. The method for preparing the resin solution for copper-clad laminates according to claim 6, characterized in that, The polyethersulfone (PES) powder is mixed with a silane coupling agent, ball-milled for modification, sieved, and then added to the mixture.

8. A method for preparing a high heat-resistant copper-clad laminate, characterized in that, Includes the following steps: Impregnate fiberglass cloth with the resin solution described in any one of claims 1-5 or the resin solution obtained by the preparation method described in any one of claims 6-7, and dry at 100-180°C for 10-30 minutes to obtain a semi-cured sheet. Take several prepreg sheets, stack them together, cut them, cover both sides with copper foil, and hot press at 190-230℃ for 80-240 minutes to obtain a high heat-resistant copper-clad laminate.

9. A high heat-resistant copper-clad laminate, characterized in that, The resin adhesive obtained by the resin solution according to any one of claims 1-5 or the preparation method according to any one of claims 6-7.

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