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

Abstract

The invention provides a resin glue solution for a copper-clad plate, a high-heat-resistance copper-clad plate and a preparation method, and relates to the technical field of copper-clad plates. According to the resin glue solution for the copper-clad plate, common epoxy resin and isocyanate modified epoxy resin are used as base materials, and organic micro-powder PES powder with good heat resistance is adopted. Compared with inorganic micro-powder, the organic micro-powder PES powder has more excellent dispersing performance. Furthermore, organic micro-powder polyether sulfone PES powder with a relatively high proportion is adopted, and the organic micro-powder polyether sulfone PES powder is compatible with octa-p-aminophenyl-POSS. The compatibility of the 8-p-aminophenyl-POSS not only promotes the dispersion of the organic micro-powder PES powder, but also the amino group in the 8-p-aminophenyl can directly react with the epoxy resin, so that the heat resistance of the epoxy resin is further improved. By adopting the octa-p-aminophenyl-POSS containing silicon element and polyamino, the peel strength, toughness and water resistance of the resin glue solution are better improved, and the comprehensive performance of the obtained copper-clad plate is further improved.

Description

Technical Field

[0001] The present invention relates to the technical field of copper clad laminates, and in particular to a resin adhesive for copper clad laminates, a high-heat-resistant copper clad laminate and a preparation method thereof. Background Art

[0002] Copper clad laminate, also known as base material, is widely used in computers, mobile communications and other fields.

[0003] Since 2006, the industry has entered the era of lead-free soldering, which has led to higher soldering temperatures, so the heat resistance requirements for copper clad laminates have also increased accordingly.

[0004] Epoxy resins have excellent physical, mechanical, and electrical insulation properties and are widely used in coatings, adhesives, and other fields. They are also often used as the main resin in copper-clad laminates. Common copper-clad laminate preparation methods on the market often use brominated epoxy resins, but brominated epoxy resins have low glass transition temperatures and cannot meet the high soldering temperature requirements when using lead-free soldering. Multifunctional epoxy resins can improve the heat resistance of copper-clad laminates, meeting the requirements of lead-free soldering. Therefore, it is particularly important to prepare copper-clad laminates with high heat resistance, low cost, and simple preparation processes.

[0005] Thanks to the implementation of the EU RoHS directive, the global electronics industry has long 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 approximately 50 seconds longer. Consequently, the heat applied to the substrate during the soldering process increases significantly, requiring copper-clad laminates to possess superior heat resistance. Traditional FR-4 copper-clad laminates, however, have a glass transition temperature of only around 130°C and a thermal decomposition temperature of only 300-310°C. These low heat resistance qualities make them suitable for general electronic applications but prohibitive for high-density interconnects and integrated circuits. The rapid development and rapid advancement of electronic products are driving the demand for thinner, lighter, and more multi-layered printed circuits. This demands that substrate materials exhibit higher glass transition temperatures, heat resistance, and low thermal expansion, while maintaining consistent performance to enhance interconnection and installation reliability.

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

[0007] The main raw materials include: 30-60 parts of low-bromine epoxy resin, 10-30 parts of high-bromine epoxy resin, and 5-10 parts of tetrafunctional epoxy resin. Also included are 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. 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 has excellent comprehensive performance and meets the requirements for high-end PCBs. However, a relatively large amount of inorganic filler is used in this invention. Inorganic fillers are difficult to disperse, which can easily increase the viscosity of the adhesive, make processing difficult, and result in poor mechanical strength and toughness of the matrix and reduced bonding performance. Summary of the Invention

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

[0009] In a first aspect, the present application provides a resin adhesive for a copper clad laminate:

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

[0011] 40-120 parts of epoxy resin; 40-80 parts of isocyanate-modified epoxy resin; 30-60 parts of polyethersulfone PES powder; 20-40 parts of octa-p-aminophenyl-POSS; 8-20 parts of curing agent; 0.1-2 parts of curing accelerator; 50-120 parts of acetone; 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, a silane coupling agent is attached to the surface of the polyethersulfone PES powder, and the silane coupling agent is an amino group-containing silane coupling agent and / or an epoxy group-containing silane coupling agent.

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

[0016] Furthermore, the amino group-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 epoxy resin and bisphenol A epoxy resin; the thiazole accelerator is one or more of imidazole, 2-methylimidazole, 1-benzylbenzene-2-ethylimidazole, 2-phenylimidazole, 2-ethyl-4-methylimidazole, 1-aminoethyl-2-methylimidazole, and 1-cyanoethylimidazole; 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] In a second aspect, the present application provides a method for preparing a resin adhesive for a copper clad laminate, comprising the following steps:

[0019] The epoxy resin and isocyanate modified epoxy resin are evenly mixed, acetone is added and stirred, and then polyethersulfone PES powder, octa-p-aminophenyl-POSS, curing agent and curing accelerator are added to the mixture, and stirred at 25-40° C. to obtain resin glue for copper clad laminate.

[0020] The polyethersulfone PES powder is mixed with a silane coupling agent, subjected to ball milling modification, and sieved before being used in a resin glue for copper plates.

[0021] In a third aspect, the present application provides a method for preparing a copper clad laminate, comprising the following steps:

[0022] The glass fiber cloth is impregnated with the resin adhesive of the present application or the resin adhesive obtained by the preparation method described in the present application, and dried at 100-180°C for 10-30 minutes to obtain a semi-cured sheet; several semi-cured sheets are stacked together, cut, covered with copper foil on both sides, and hot pressed at 190-230°C for 80-240 minutes to obtain a high heat-resistant copper clad laminate.

[0023] In a fourth aspect, the present application provides a copper clad laminate comprising the resin adhesive described in the present application or the resin adhesive obtained by the preparation method described in the present application.

[0024] Beneficial effects: 1. The resin glue for copper clad laminates of the present application uses ordinary epoxy resin and isocyanate modified epoxy resin as base materials, and adds organic micropowder polyethersulfone PES powder with good heat resistance. Compared with inorganic micropowder, organic micropowder polyethersulfone PES powder has better dispersion performance. Furthermore, a larger proportion of organic micropowder polyethersulfone PES powder is used in combination with octa-p-aminophenyl-POSS. The combination of octa-p-aminophenyl-POSS not only promotes the dispersion of organic micropowder polyethersulfone PES powder, but also the amino group in the octa-p-aminophenyl can directly react with epoxy resin, further improving the heat resistance of epoxy resin. The use of octa-p-aminophenyl-POSS containing silicon and polyamino groups can better improve the peel strength, toughness and water resistance of the resin glue, 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 its dosage is optimized. The use of polyether polyol effectively promotes the dispersion of polyethersulfone (PES) powder, while also ensuring that the obtained cured sheet has an appropriate degree of crosslinking, improving 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 shortcomings of the aromatic amine curing agent alone, which has poor toughness and adhesion, resulting in a copper clad laminate with high overall performance.

[0026] 3. The surface modification of polyethersulfone PES powder with silane coupling agent improves the dispersion performance, adhesive performance, adhesion performance and mechanical properties; further optimization of amino silane coupling agent improves the comprehensive performance of the obtained copper clad laminate. DETAILED DESCRIPTION

[0027] In order to make the technical solution of the present invention clearer, the present invention is 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, includes the following preparation steps:

[0029] 1) Preparation of silane coupling agent-modified polyethersulfone (PES) powder: KH-550 and ethanol were mixed in 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. The hydrolyzed silane solution was then sprayed onto the PES powder with stirring at 200 rpm and allowed to stand for 1 hour to allow silane adsorption. Zirconia balls and pretreated PES powder were then added at a ball-to-powder ratio of 5:1. The rotation speed was set at 300 rpm, and the mixture was ball milled for 4 hours. Undispersed agglomerates were removed through a 400-mesh sieve to obtain silane coupling agent-modified polyethersulfone (PES) powder.

[0030] 2) Preparation of a resin adhesive for copper clad laminates: Raw materials were weighed according to the formula, and epoxy resin and isocyanate-modified epoxy resin were uniformly mixed. Acetone was then added, and the mixture was stirred at 60°C for 2 hours to obtain a mixed solution. Polyethersulfone (PES) powder, octa-p-aminophenyl-POSS, a curing agent, and a curing accelerator were then added to the mixed solution, and the mixture was stirred at 30°C for 1.5 hours to obtain the adhesive for copper clad laminates.

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

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

[0033] The prepregs were stacked together, cut, covered with copper foil on both sides, and hot-pressed to obtain a high heat-resistant copper-clad laminate. The hot-pressing pressure was 350 PSI, the temperature was 200°C, and the time was 100 min.

[0034] Examples 2 to 3 are methods for preparing a high-heat-resistant copper-clad laminate. The difference from Example 1 is that the weights and types of raw materials used are different, as shown in Table 1.

[0035] Table 1. Types and weights of raw materials 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, an equal amount of 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).

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

[0041] Example 8, a method for preparing a high heat-resistant copper clad laminate, differs from Example 1 in that, in the curing agent, an equal amount of 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).

[0042] Example 9, a method for preparing a high heat-resistant copper clad laminate, differs from Example 1 in that, in the curing agent, an equal amount of 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).

[0043] Example 10, a method for preparing a high heat-resistant copper clad laminate, differs from Example 1 in that, in the curing agent, an equal amount of 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).

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

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

[0046] Example 13, a method for preparing a high-heat-resistant copper-clad laminate, differs from Example 1 in that, in the curing agent, an equal amount of γ-glycidyloxypropyltrimethoxysilane is used 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 the curing agent, an equal amount of polyethersulfone PES powder (particle size 10 μm) is used to replace the modified polyethersulfone PES powder in step 1).

[0048] Comparative Example 1 is a method for preparing a high-heat-resistant copper-clad laminate. The difference from Example 1 is that octa-p-aminophenyl-POSS is replaced by an equal amount of octa-epoxy cage-type silsesquioxane.

[0049] Comparative Example 2 is a method for preparing a high-heat-resistant copper-clad laminate. The difference from Example 1 is that methylphenyl silicone resin is used to replace octa-p-aminophenyl-POSS in equal amounts.

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

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

[0052] 1. Glass transition temperature Tg: Refer to GB / T 40396-2021 to test the Tg of the adhesive for copper clad laminate.

[0053] 2. Water absorption rate: Refer to GB / T1462-2005 for testing. Immerse the copper clad laminate in a constant temperature water bath at 25°C for 24 hours, and measure the weight change before and after immersion to determine the water absorption rate of the copper clad laminate.

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

[0055] 4. Bending strength: The copper clad laminate was tested with reference to 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 tests was 5, the test temperature was 23°C, the relative humidity was 50%, and the specimen conditioning time was 30 h.

[0056] 5. PCT: Cook in a pressure cooker at 121℃ 105KPa for 1h, immerse in a tin furnace at 288℃, and record the time for the board to explode and delaminate.

[0057] Table 1. Properties of resin adhesives and copper clad laminates obtained using the preparation methods of Examples 1 to 14 and Comparative Examples 1 to 3

[0058]

[0059] The experimental data from Examples 1 and 4 were superior to those from Example 5, demonstrating that a curing agent composition of a polyether polyol and aromatic amine curing agent in a ratio of (1-3):1 is preferred, simultaneously improving heat resistance, peel strength, flexural strength, and PCT performance. The combination of a polyether polyol and an aromatic amine curing agent exhibits excellent compatibility. The use of a polyether polyol improves the dispersion of the 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 also improves heat resistance.

[0060] The overall experimental data of Examples 8 and 9 are better than those of Examples 6 and 7, and the overall experimental data of Examples 6 and 7 are better than those of Examples 6 and 7, indicating that the performance of Examples 1 and 4 is better. This indicates that the use of a combination of a polyether polyol and an aromatic amine curing agent as a curing agent and a combination of a polyether diol, a polyether triol, and a polyether tetraol as a polyol further improves the peel strength, flexural strength, PCT performance, water resistance, and heat resistance of the resin adhesive. The use of polyols with different molecular weights and different numbers of functional groups as curing agents allows the prepared cured sheet to have a moderate degree of crosslinking, 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, and the amount of small molecule curing agent is reduced, resulting in a decrease in the crosslinking degree and adhesion performance of the cured sheet.

[0062] The experimental data for Tg, peel strength, flexural strength, and PCT in Examples 11 and 12 show that the use of a polyether polyol and aromatic amine curing agent in combination, in conjunction with the other components in the adhesive, improves the overall performance of the copper-clad laminate. This may be because the use of the polyether polyol effectively promotes the dispersion of the polyethersulfone (PES) powder and simultaneously imparts an appropriate degree of crosslinking to the cured sheet formed from the adhesive, thereby improving toughness, adhesion, mechanical properties, and heat resistance.

[0063] The overall performance of Example 1 was superior to that of Examples 13 and 14, indicating that surface modification of polyethersulfone (PES) powder with a silane coupling agent improved its dispersibility, adhesive properties, adhesion, and mechanical properties. Furthermore, amino-silane coupling agents were preferred, further enhancing overall performance. This may be because the amino groups on the surface of the modified polyethersulfone (PES) powder can directly react with the epoxy groups in the epoxy resin, effectively modifying the epoxy resin.

[0064] The overall performance of Example 1 is better than Comparative Examples 1 to 3, showing that in the glue, eight pairs of aminophenyl-POSS are used in combination with other raw materials in the glue to improve the overall performance of the copper clad plate. The possible reason is that, relative to eight epoxy-based cage-type silsesquioxanes, eight pairs of aminophenyl-POSS can directly react with the epoxy group in the epoxy resin, and the epoxy resin can be modified better; relative to the epoxy group, eight pairs of aminophenyl-POSS and modified polyethersulfone PES powder surface contain the same polar group amino group, have good affinity, and can better promote the dispersion of modified polyethersulfone PES powder; without using eight pairs of aminophenyl-POSS in the glue, the water resistance of the cured sheet is reduced, and toughness and adhesion performance are reduced.

[0065] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A resin glue for copper clad laminate, characterized in that: Calculated by weight, it includes the following components: 40-120 parts of epoxy resin; 40-80 parts of isocyanate modified epoxy resin; 30-60 parts of polyethersulfone PES powder; 20-40 parts of octa-p-aminophenyl-POSS; 8-20 parts of curing agent; 0.1-2 parts of curing accelerator; 50-120 parts of acetone; 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.

2. The resin glue for copper clad laminate according to claim 1, characterized in that The curing agent is a composition of polyether polyol and aromatic amine curing agent in a ratio of (1-3):

1.

3. The resin glue for copper clad laminate according to claim 2, 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.

4. The resin glue for copper clad laminate according to claim 1, characterized in that A silane coupling agent is attached to the surface of the polyethersulfone PES powder, and the silane coupling agent is an amino group-containing silane coupling agent and / or an epoxy group-containing silane coupling agent.

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

6. The resin glue for copper clad laminate according to claim 1, characterized in that: The epoxy resin is one or more of bisphenol F epoxy resin and bisphenol A epoxy resin; the thiazole accelerator is one or more of imidazole, 2-methylimidazole, 1-benzylbenzene-2-ethylimidazole, 2-phenylimidazole, 2-ethyl-4-methylimidazole, 1-aminoethyl-2-methylimidazole, and 1-cyanoethylimidazole; 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.

7. The method for preparing the resin glue for copper clad laminate according to claim 1, wherein: The following steps are involved: The epoxy resin and isocyanate modified epoxy resin are evenly mixed, acetone is added and stirred, and then polyethersulfone PES powder, octa-p-aminophenyl-POSS, curing agent and curing accelerator are added to the mixture, and stirred at 25-40° C. to obtain resin glue for copper clad laminate.

8. The method for preparing the resin glue for copper clad laminate according to claim 7, wherein: The polyethersulfone PES powder is mixed with the silane coupling agent, subjected to ball milling modification, sieved, and then added to the mixed solution.

9. A method for preparing a high heat-resistant copper-clad laminate, characterized in that: The following steps are involved: The glass fiber cloth is impregnated with the resin adhesive according to any one of claims 1 to 6 or the resin adhesive obtained by the preparation method according to any one of claims 7 to 8, and dried at 100 to 180° C. for 10 to 30 minutes to obtain a prepreg; Take several prepregs and stack them together, cut them, cover both sides with copper foil, and hot press them at 190-230℃ for 80-240min. A high heat-resistant copper clad laminate is obtained.

10. A high heat-resistant copper-clad laminate, characterized in that: The resin glue obtained by the resin glue according to any one of claims 1 to 6 or the preparation method according to any one of claims 7 to 8.

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