High-adhesive-force epoxy molding compound with lignin and preparation method of high-adhesive-force epoxy molding compound

Abstract

The invention belongs to the technical field of composite material packaging, and discloses a high-adhesive-force epoxy molding compound with lignin and a preparation method of the high-adhesive-force epoxy molding compound. The epoxy molding compound comprises the following components: a mixture of epoxy resin, phenolic resin and lignin, an inorganic filler, a coloring agent, a release agent, a curing accelerator, an ion trapping agent and a coupling agent. The epoxy molding compound prepared by replacing part of phenolic resin with lignin and adopting a method of pre-melting lignin and phenolic resin in advance has the characteristics of improved glass transition temperature (Tg), high adhesive force, high reliability and environmental protection, reduces dependence on fossil fuel, and realizes sustainable development.

Description

Technical Field

[0001] The present invention relates to the technical field of composite material packaging, and in particular to a high-adhesion epoxy molding compound containing lignin and a preparation method thereof. Background Art

[0002] Epoxy Molding Compound (EMC), a thermosetting composite material based on epoxy resin, is widely used in the semiconductor industry for chip encapsulation and protection. In the 1960s, with the rapid development of integrated circuit (IC) technology, traditional metal / ceramic packaging was gradually replaced by plastic packaging due to its high cost and complex manufacturing process. Epoxy molding compound, due to its excellent performance, became the mainstream choice. In recent years, with the development of new technology industries, epoxy molding compounds have gained widespread application in the electronic packaging field, resulting in an increasing demand for composite materials.

[0003] Among them, epoxy and phenolic resin curing agents are one of the main raw materials for epoxy molding compounds. Excellent mechanical and electrical properties are particularly important for the various performance properties of packaging materials. Both are mainly derived from petrochemical products. Their core raw materials come from petroleum derivatives, mainly including bisphenol A (BPA), epichlorohydrin (ECH), phenol (petroleum / coal), and formaldehyde (natural gas / coal). However, in recent years, with the overexploitation of fossil resources, problems such as resource depletion and carbon dioxide emissions have increasingly serious impacts on the earth's environment. The use of natural raw materials has become a research hotspot in the future, and renewable resources (such as plant-based and waste-derived raw materials) are being explored to reduce dependence on fossil fuels. At the same time, the excellent mechanical and electrical properties of epoxy molding compounds must also be guaranteed.

[0004] Patent CN118742588A discloses a sealing resin composition and a semiconductor device. This invention utilizes a phenolic curing agent derived from plant-derived raw materials to produce an epoxy resin composition exhibiting excellent practical properties, including fluidity, curability, and electrical reliability. While the epoxy composition prepared using this phenolic curing agent exhibits excellent practicality, the complex preparation process for biomass-modified phenolic resins is unsuitable for large-scale industrial production and is prone to batch instability. Furthermore, the performance of the composition does not significantly improve compared to existing petroleum-based curing agents.

[0005] Therefore, the existing technology needs further development and improvement. In line with the development trend of sustainable development and environmental protection, more and more research is being conducted on bio-based alternatives to epoxy and phenolic resins. Therefore, selecting suitable biomass to replace epoxy or phenolic resins, solving the problem of simple preparation process, facilitating industrial development, and ensuring excellent performance, is a technical problem that technicians in this field urgently need to solve. Summary of the Invention

[0006] The present invention addresses the problems of the above-mentioned prior art and provides a high-adhesion epoxy molding compound containing lignin and a preparation method thereof. The prepared epoxy molding compound has the characteristics of increased glass transition temperature (Tg), high adhesion, high reliability, and environmental friendliness, reducing dependence on fossil fuels and achieving sustainable development. Specifically, by replacing part of the phenolic resin curing agent with lignin, an epoxy molding compound with high crosslinking density and high adhesion is provided. The present invention can provide an EMC with high reliability for various packaging forms known in the art, such as SOP, QFN, PDFN, and SOT.

[0007] The present invention is achieved through the following technical solutions:

[0008] In one aspect, a high-adhesion epoxy molding compound with lignin is provided, comprising the following components in parts by mass: 4-10 parts of epoxy resin, 3-10 parts of a mixture of phenolic resin and lignin, 70-90 parts of an inorganic filler, 0.1-0.3 parts of a colorant, 0.2-0.6 parts of a release agent, 0.1-0.5 parts of a curing accelerator, 0.2-1.5 parts of an ion scavenger, and 0.1-0.3 parts of a coupling agent;

[0009] The mass ratio of phenolic resin to lignin is 2-10:1.

[0010] Preferably, the epoxy resin is selected from one or more of o-cresol epoxy resin, dicyclopentadiene epoxy resin, polyaromatic epoxy resin, trifunctional epoxy resin, tetrafunctional epoxy resin, biphenyl epoxy resin, and naphthalene epoxy resin.

[0011] Preferably, the phenolic resin is selected from one or more of o-methylphenolic resin, biphenylphenolic resin, polyaromatic phenolic resin, and phenol aralkylphenolic resin.

[0012] Preferably, the lignin is one or more of sulfate lignin, alkali lignin, organic solvent lignin, and enzymatic lignin.

[0013] Preferably, the preparation method of the enzymatically hydrolyzed lignin is as follows:

[0014] The wood and straw are crushed and ground into 20-80 mesh, and enzymatic hydrolysis is carried out for 36 hours at 30-50°C and pH 4-5 using laccase + MnP; the temperature is raised to 80°C and kept warm for 10 minutes, and the residue is removed by centrifugation or filtration, and the pH is adjusted to 2-3. After lignin is precipitated, it is collected by centrifugation and extracted with ethyl acetate or dioxane, and finally small molecular impurities are removed to prepare enzymatic lignin; the enzymatic lignin structural formula is:

[0015]

[0016] Preferably, the inorganic filler is selected from one or more of crystalline silica, fused silica, spherical silica, alumina, talc, kaolin, carbon fiber, and glass fiber.

[0017] Preferably, the colorant is carbon black commonly used in the art, without particular limitation.

[0018] Preferably, the release agent is selected from one of palm wax, montanate wax, polyethylene wax, oxidized polyethylene wax and polyamide wax.

[0019] Preferably, the curing accelerator is selected from one or more of imidazole compounds, tertiary amine compounds, organic phosphine compounds, and amide compounds.

[0020] Preferably, the ion capture agent is an anion capture agent.

[0021] Preferably, the coupling agent is one or more of methyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, and methyltriethoxysilane.

[0022] In another aspect, a method for preparing a high-adhesion epoxy molding compound containing lignin is provided, the method comprising the following steps: first, weighing raw materials according to mass fraction, then pre-melting phenolic resin and lignin in a homogenizer at a pre-melting temperature of 130 to 150° C. for 2 hours; then, adding the pre-melted phenolic resin and lignin, epoxy resin, inorganic filler, colorant, release agent, curing accelerator, ion scavenger, and coupling agent to a high-speed mixer in sequence to obtain a premix;

[0023] The premix is transferred to an extruder, fully kneaded and mixed, cooled and crushed to obtain a high-adhesion epoxy molding compound with lignin; wherein the melting section temperature of the extruder is 100-130°C, and the extrusion temperature is 85-100°C.

[0024] In a third aspect, the present invention provides sustainable development applications of high-adhesion epoxy molding compounds containing lignin in integrated circuit packaging.

[0025] The beneficial effects of the present invention are:

[0026] (1) The enzymatic lignin provided by the present invention partially replaces phenolic resin. Enzymatic lignin is a natural polymer derived from plants and is biodegradable. Replacing petroleum-based phenolic resin can reduce carbon footprint. By introducing enzymatic lignin, reliance on petrochemical resources is reduced, meeting the requirements of green and environmentally friendly manufacturing. At the same time, enzymatic lignin is abundant in sources and relatively affordable, laying an important foundation for future price competitiveness.

[0027] (2) The use of phenolic resin as a curing agent in epoxy molding compounds has a low crosslinking density, resulting in poor mechanical and thermal properties. Enzymatically hydrolyzed lignin is rich in functional groups such as phenolic hydroxyl, hydroxyl, methoxyl, carbonyl and carboxyl groups, which can undergo crosslinking reactions with the epoxy groups of epoxy resin, replacing part of the phenolic resin as a curing agent and improving the crosslinking density. Therefore, the replacement of part of the phenolic resin with enzymatically hydrolyzed lignin can solve the problems of low crosslinking density and adhesion. Under the synergistic effect of enzymatically hydrolyzed lignin and phenolic resin, the glass transition temperature Tg of the prepared epoxy molding compound is significantly improved; at the same time, the enzymatically hydrolyzed lignin contains rich polar groups, which increases the adhesion of the prepared epoxy molding compound to copper and silver. Secondly, the aromatic ring structure of lignin gives it self-flame retardant properties, which can reduce the amount of traditional flame retardants (such as brominated epoxy resin), reduce smoke toxicity, and comply with green technology.

[0028] (3) In order to avoid stratification and pores in the packaged product, the present invention increases the specific surface area of the resin by fully crushing the phenolic resin and enzymatic lignin, pre-melting them in a homogenizer according to the proportion, and can be fully mixed to effectively improve their compatibility and avoid phase separation. At the same time, the enzymatic lignin provided by the present invention has high heat resistance compared to phenolic resin. In addition, the present invention uses high-temperature resistant coupling agents, adhesion agents and ion capture agents to further improve the heat resistance of the epoxy molding compound, thereby reducing the internal stress of the epoxy molding compound and internal components during the integrated circuit packaging process. It is suitable for high-temperature packaging scenarios (such as automotive electronics) and improves the reliability of integrated circuit packaging. DETAILED DESCRIPTION

[0029] The contents of the present invention will be described in detail below. This embodiment is implemented based on the technical solution of the present invention and involves detailed implementation plans and operating procedures. However, the scope of protection of the present invention is not limited to the following specific embodiments. The terms used in the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0030] The raw materials used are as follows:

[0031] Epoxy resin: naphthalene-based epoxy resin (DIC Corporation); biphenyl-based epoxy resin (Mitsubishi Chemical Corporation).

[0032] Phenolic resin: phenol aralkylphenol resin (Meiwa Chemicals Co., Ltd.).

[0033] Inorganic filler: spherical silica (Jiangsu Lianrui New Materials Co., Ltd.).

[0034] Colorant: Carbon black (Sichuan Zhenghao Special Carbon Black Technology Co., Ltd.).

[0035] Release agent: oxidized polyethylene wax; palm wax (Shanghai Yuexiang).

[0036] Curing accelerator: triphenylphosphine-1,4-benzoquinone adduct (TPP-BQ) (Shanghai Huichuang).

[0037] Ion scavenger: anion scavenger (Ningbo Sumeitong).

[0038] Coupling agents: 3-mercaptopropyltrimethoxysilane and methyltrimethoxysilane (Chongyue Trading).

[0039] Preparation method of enzymatic lignin:

[0040] The wood and straw are crushed and ground into smaller particle sizes (20-80 meshes), and laccase + MnP are used in combination to carry out enzymatic hydrolysis at 30-50°C and pH 4-5 for 36 hours, while the degradation efficiency is dynamically monitored. The temperature is raised to 80°C (kept warm for 10 minutes), and the residue (cellulose / hemicellulose) is removed by centrifugation or filtration. The pH is adjusted to 2-3, and lignin is precipitated and collected by centrifugation. The enzymatically hydrolyzed lignin is extracted with ethyl acetate or dioxane, and finally small molecular impurities (such as monosaccharides and phenolic acids) are removed to prepare enzymatically hydrolyzed lignin.

[0041] Example 1

[0042] A high-adhesion epoxy molding compound containing lignin and a preparation method thereof, wherein the preparation method comprises the following steps:

[0043] First, 3.9 g of phenol aralkyl phenolic resin and 0.4 g of enzymatically hydrolyzed lignin were pre-melted in a homogenizer (130-150° C., 2 h), and then 5.7 g of naphthalene epoxy resin, 0.5 g of biphenyl epoxy resin, 87.5 g of spherical silica with a D90 of 75 μm, 0.18 g of palm wax, 0.3 g of oxidized polyethylene wax, 0.3 g of methyltrimethoxysilane, 0.2 g of 3-mercaptopropyltrimethoxysilane, 0.22 g of carbon black, 0.5 g of anion scavenger, and 0.3 g of TPP-BQ were added to a high-speed mixer in this order to obtain a premix;

[0044] The premix is transferred to an extruder, thoroughly kneaded and mixed, cooled and pulverized to obtain a high-adhesion epoxy molding compound containing lignin; the extruder has a melting zone temperature of 100-130°C and an extrusion temperature of 85-100°C. The extruder is then naturally cooled and pulverized to obtain a powder, which is preformed into a cake to obtain an epoxy molding compound containing enzymatically degraded lignin.

[0045] Example 2

[0046] A high-adhesion epoxy molding compound containing lignin and a preparation method thereof, wherein the preparation method comprises the following steps:

[0047] First, 3.7 g of phenol aralkyl phenolic resin and 0.6 g of enzymatically hydrolyzed lignin were pre-melted in a homogenizer (130-150° C., 2 h), and then 5.7 g of naphthalene epoxy resin, 0.5 g of biphenyl epoxy resin, 87.5 g of spherical silica with a D90 of 75 μm, 0.18 g of palm wax, 0.3 g of oxidized polyethylene wax, 0.3 g of methyltrimethoxysilane, 0.2 g of 3-mercaptopropyltrimethoxysilane, 0.22 g of carbon black, 0.5 g of anion scavenger, and 0.3 g of TPP-BQ were added to a high-speed mixer in this order to obtain a premix;

[0048] The premix is transferred to an extruder, thoroughly kneaded and mixed, cooled and pulverized to obtain a high-adhesion epoxy molding compound containing lignin; the extruder has a melting zone temperature of 100-130°C and an extrusion temperature of 85-100°C. The extruder is then naturally cooled and pulverized to obtain a powder, which is preformed into a cake to obtain an epoxy molding compound containing enzymatically degraded lignin.

[0049] Example 3

[0050] A high-adhesion epoxy molding compound containing lignin and a preparation method thereof, wherein the preparation method comprises the following steps:

[0051] First, 3.5 g of phenol aralkyl phenolic resin and 0.8 g of enzymatically hydrolyzed lignin were pre-melted in a homogenizer (130-150° C., 2 h), and then 5.7 g of naphthalene epoxy resin, 0.5 g of biphenyl epoxy resin, 87.5 g of spherical silica with a D90 of 75 μm, 0.18 g of palm wax, 0.3 g of oxidized polyethylene wax, 0.3 g of methyltrimethoxysilane, 0.2 g of 3-mercaptopropyltrimethoxysilane, 0.22 g of carbon black, 0.5 g of anion scavenger, and 0.3 g of TPP-BQ were added to a high-speed mixer in this order to obtain a premix;

[0052] The premix is transferred to an extruder, thoroughly kneaded and mixed, cooled and pulverized to obtain a high-adhesion epoxy molding compound containing lignin; the extruder has a melting zone temperature of 100-130°C and an extrusion temperature of 85-100°C. The extruder is then naturally cooled and pulverized to obtain a powder, which is preformed into a cake to obtain an epoxy molding compound containing enzymatically degraded lignin.

[0053] Example 4

[0054] A high-adhesion epoxy molding compound containing lignin and a preparation method thereof, wherein the preparation method comprises the following steps:

[0055] First, 3.3 g of phenol aralkyl phenolic resin and 1 g of enzymatically hydrolyzed lignin were pre-melted in a homogenizer (130-150° C., 2 h), and then 5.7 g of naphthalene epoxy resin, 0.5 g of biphenyl epoxy resin, 87.5 g of spherical silica with a D90 of 75 μm, 0.18 g of palm wax, 0.3 g of oxidized polyethylene wax, 0.3 g of methyltrimethoxysilane, 0.2 g of 3-mercaptopropyltrimethoxysilane, 0.22 g of carbon black, 0.5 g of anion scavenger, and 0.3 g of TPP-BQ were added to a high-speed mixer in this order to obtain a premix;

[0056] The premix is transferred to an extruder, thoroughly kneaded and mixed, cooled and pulverized to obtain a high-adhesion epoxy molding compound containing lignin; the extruder has a melting zone temperature of 100-130°C and an extrusion temperature of 85-100°C. The extruder is then naturally cooled and pulverized to obtain a powder, which is preformed into a cake to obtain an epoxy molding compound containing enzymatically degraded lignin.

[0057] Comparative Example 1

[0058] The difference from Example 3 is that the addition of enzymatic lignin is omitted. The specific steps are as follows:

[0059] 5.7 g of naphthalene epoxy resin, 0.5 g of biphenyl epoxy resin, 4.3 g of phenol aralkyl phenolic resin, 87.5 g of spherical silica with a D90 of 75 μm, 0.18 g of palm wax, 0.3 g of oxidized polyethylene wax, 0.3 g of methyltrimethoxysilane, 0.2 g of 3-mercaptopropyltrimethoxysilane, 0.22 g of carbon black, 0.5 g of anion scavenger, and 0.3 g of TPP-BQ were added to a high-speed mixer in sequence to obtain a premix;

[0060] The premix is transferred to an extruder, thoroughly kneaded and mixed, cooled and pulverized to obtain a high-adhesion epoxy molding compound containing lignin; the extruder has a melting zone temperature of 100-130°C and an extrusion temperature of 85-100°C. The extruder is then naturally cooled and pulverized to obtain a powder, which is preformed into a cake to obtain an epoxy molding compound containing enzymatically degraded lignin.

[0061] Comparative Example 2

[0062] The difference from Example 3 is that the step of pre-melting the phenol aralkylphenolic resin and the enzymatic lignin is omitted. The specific steps are as follows:

[0063] 5.7 g of naphthalene epoxy resin, 0.5 g of biphenyl epoxy resin, 3.5 g of phenol aralkyl phenolic resin, 0.8 g of enzymatic lignin, 87.5 g of spherical silica with a D90 of 75 μm, 0.18 g of palm wax, 0.3 g of oxidized polyethylene wax, 0.3 g of methyltrimethoxysilane, 0.2 g of 3-mercaptopropyltrimethoxysilane, 0.22 g of carbon black, 0.5 g of anion scavenger, and 0.3 g of TPP-BQ were added to a high-speed mixer in sequence to obtain a premix;

[0064] The premix is transferred to an extruder, thoroughly kneaded and mixed, cooled and pulverized to obtain a high-adhesion epoxy molding compound containing lignin; the extruder has a melting zone temperature of 100-130°C and an extrusion temperature of 85-100°C. The extruder is then naturally cooled and pulverized to obtain a powder, which is preformed into a cake to obtain an epoxy molding compound containing enzymatically degraded lignin.

[0065] Comparative Example 3

[0066] The difference from Example 3 is that the addition of phenol aralkylphenol-formaldehyde resin is omitted, and the specific steps are as follows:

[0067] 5.7 g of naphthalene epoxy resin, 0.5 g of biphenyl epoxy resin, 4.3 g of enzymatically hydrolyzed lignin, 87.5 g of spherical silica with a D90 of 75 μm, 0.18 g of palm wax, 0.3 g of oxidized polyethylene wax, 0.3 g of methyltrimethoxysilane, 0.2 g of 3-mercaptopropyltrimethoxysilane, 0.22 g of carbon black, 0.5 g of anion scavenger, and 0.3 g of TPP-BQ were added to a high-speed mixer in sequence to obtain a premix;

[0068] The premix is transferred to an extruder, thoroughly kneaded and mixed, cooled and pulverized to obtain a high-adhesion epoxy molding compound containing lignin; the extruder has a melting zone temperature of 100-130°C and an extrusion temperature of 85-100°C. The extruder is then naturally cooled and pulverized to obtain a powder, which is preformed into a cake to obtain an epoxy molding compound containing enzymatically degraded lignin.

[0069] Epoxy molding compounds are evaluated primarily through the following test methods:

[0070] The specific testing process is as follows:

[0071] 1. Referring to GB / T40564-2021 "Test Method for Epoxy Molding Compounds for Electronic Packaging", the spiral flow length, gelation time, flash, viscosity, strength modulus, hot hardness, appearance inspection and thermal conductivity of the epoxy resin compositions prepared in Examples 1-5 and Comparative Examples 1-2 were measured;

[0072] 2. High Pressure Cooking Test (PCT): Refer to GB / T 40564-2021, temperature 121°C, humidity 100%, and two standard atmospheres for 120 hours. Weigh the sample before and after the test, and calculate the water absorption rate. Sample size requirements: diameter: 50±1mm, thickness: 3±0.2mm;

[0073] 3. TMA test (Tg): Use a static thermomechanical analyzer (TMA) in bending mode to measure the glass transition temperature (Tg) of the epoxy molding compound. The test sample size is 4×4×10mm. The starting temperature is 25℃, the heating rate is 5℃ / min, and the end temperature is 220℃.

[0074] 4. Adhesion Test: Using a molding press, the resulting EMC cake was molded onto different substrate surfaces, including copper and silver-plated substrates, at a mold temperature of 175±2°C, an injection pressure of 7.0±0.2 MPa, and a curing time of 120 seconds. Using the SEMI G69-0996 standard, a shear force was applied along the sample surface at a speed of 10 mm / min. The maximum value before the plastic encapsulation material separated from the sample was measured. Ten samples were tested for each type of adhesion test, and the average of the ten test results was used as the adhesion test result for each example.

[0075] 5. Flame Resistance Test: Place a layer of approximately 6.4mm thick absorbent cotton under an alcohol lamp. Light the alcohol lamp and adjust the flame to a height of 19mm. Clamp the spline 6.4mm from the end and place it vertically into the center of the flame for 10 seconds. After 10 seconds, move the spline at least 152mm away from the flame, while recording the flaming and glowing times with a stopwatch. Once the flame is extinguished, immediately contact the flame again at the same point for 10 seconds. Then, move the spline at least 152mm away from the flame, while recording the flaming and glowing times with a stopwatch. Five splines should be tested, resulting in 10 sets of data.

[0076] The test results are shown in Table 1:

[0077] Table 1 Test results

[0078]

[0079]

[0080] From the above table, it can be seen that with the addition of enzymatic lignin, the fluidity, glass transition temperature and copper-silver bonding strength tend to improve; Examples 1-4 show that as the amount of enzymatic lignin added increases, the above properties are significantly improved, and after the addition amount is 0.8g, the performance remains stable. Therefore, it is shown that the ratio between phenol aralkyl phenolic resin and enzymatic lignin affects the performance of the epoxy molding compound, and the epoxy molding compound prepared within a fixed ratio range has better performance. When the mass ratio of phenol aralkyl phenolic resin: enzymatic lignin is 3.5:0.8, the epoxy molding compound is better, such as good copper-silver adhesion and glass transition temperature.

[0081] Furthermore, Example 3 and Comparative Example 2 demonstrate that pre-melting the enzymatically hydrolyzed lignin and phenol aralkylphenolic resin plays a crucial role in the overall performance of the encapsulated product. The enzymatically hydrolyzed lignin has a high softening point, and insufficient pre-melting and mixing can lead to delamination and porosity in the encapsulated product. Therefore, the preparation process temperature and fine resin grinding significantly improve mixing properties, preventing delamination and porosity during the encapsulation process and resulting in excellent product stability.

[0082] It can be seen from Example 3 and Comparative Example 3 that although the enzymatically hydrolyzed lignin is rich in functional groups such as phenolic hydroxyl, hydroxyl, methoxy, carbonyl and carboxyl groups, which can undergo cross-linking reaction with the epoxy groups of the epoxy resin to increase the cross-linking density, if all enzymatically hydrolyzed lignin is used to replace the phenolic resin, the material will become dry and difficult to mix evenly during the mixing process, resulting in poor fluidity. Therefore, only after the synergistic effect of enzymatically hydrolyzed lignin and phenol aralkyl phenolic resin can the prepared epoxy molding compound have better performance.

[0083] Adding a suitable proportion of enzymatically hydrolyzed lignin to the system, which is rich in polar groups, enhances the adhesion of the resulting epoxy molding compound to copper and silver. Furthermore, the aromatic ring structure of lignin imparts self-flammability, reducing the use of traditional flame retardants (such as brominated epoxy resins), reducing smoke toxicity, and complying with green processes while also improving flame retardancy.

[0084] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present invention is limited to these examples. Within the scope of the present invention, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity.

Claims

1. A high-adhesion epoxy molding compound with lignin, characterized in that: The composition comprises the following components in parts by mass: 4-10 parts of epoxy resin, 3-10 parts of a mixture of phenolic resin and lignin, 70-90 parts of an inorganic filler, 0.1-0.3 parts of a colorant, 0.2-0.6 parts of a release agent, 0.1-0.5 parts of a curing accelerator, 0.2-1.5 parts of an ion capture agent, and 0.1-0.3 parts of a coupling agent; The mass ratio of phenolic resin to lignin is 2-10:

1.

2. The high-adhesion epoxy molding compound with lignin according to claim 1, characterized in that: The epoxy resin is selected from one or more of o-cresol epoxy resin, dicyclopentadiene epoxy resin, polyaromatic epoxy resin, trifunctional epoxy resin, tetrafunctional epoxy resin, biphenyl epoxy resin and naphthalene epoxy resin.

3. The high-adhesion epoxy molding compound containing lignin according to claim 1, characterized in that: The phenolic resin is selected from one or more of o-methylphenolic resin, biphenylphenolic resin, polyaromatic phenolic resin, and phenol aralkylphenolic resin.

4. The high-adhesion epoxy molding compound containing lignin according to claim 1, characterized in that: The lignin is one or more of sulfate lignin, alkali lignin, organic solvent lignin, and enzymatic lignin.

5. The high-adhesion epoxy molding compound containing lignin according to claim 4, characterized in that: The preparation method of the enzymatic lignin is as follows: The wood and straw are crushed and ground into 20-80 mesh, and an enzymatic hydrolysis reaction is carried out for 36 hours at 30-50°C and pH 4-5 using laccase + MnP; the temperature is raised to 80°C and kept warm for 10 minutes, and the residue is removed by centrifugation or filtration, and the pH is adjusted to 2-3. After lignin is precipitated, it is collected by centrifugation and extracted with ethyl acetate or dioxane. Finally, small molecular impurities are removed to prepare enzymatic hydrolyzed lignin.

6. The high-adhesion epoxy molding compound containing lignin according to claim 1, characterized in that: The inorganic filler is selected from one or more of crystalline silica, fused silica, spherical silica, alumina, talc, kaolin, carbon fiber, and glass fiber.

7. The high-adhesion epoxy molding compound containing lignin according to claim 1, characterized in that: The release agent is selected from one of palm wax, montanate wax, polyethylene wax, oxidized polyethylene wax and polyamide wax.

8. The high-adhesion epoxy molding compound containing lignin according to claim 1, characterized in that: The curing accelerator is selected from one or more of imidazole compounds, tertiary amine compounds, organic phosphine compounds, and amide compounds.

9. The high-adhesion epoxy molding compound containing lignin according to claim 1, characterized in that: The coupling agent is one or more of methyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, and methyltriethoxysilane.

10. The method for preparing the high-adhesion epoxy molding compound containing lignin according to claim 1, characterized in that: The method comprises the following steps: first, weighing raw materials according to mass fraction, then pre-melting phenolic resin and lignin in a homogenizer at a pre-melting temperature of 130-150° C. for 2 hours; then, adding the pre-melted phenolic resin and lignin, epoxy resin, inorganic filler, colorant, release agent, curing accelerator, ion scavenger, and coupling agent into a high-speed mixer in sequence to obtain a premix; The premix is transferred to an extruder, fully kneaded and mixed, cooled and crushed to obtain a high-adhesion epoxy molding compound with lignin; wherein the melting section temperature of the extruder is 100-130°C, and the extrusion temperature is 85-100°C.

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