Resin composition and preparation method thereof

Abstract

The invention relates to the technical field of high polymer materials, and particularly discloses a resin composition and a preparation method thereof, the resin composition comprises epoxy resin, a curing agent, a curing accelerator, a filler, a coupling agent and a CTE reducing auxiliary agent; the epoxy equivalent of the epoxy resin is [207-221] and [450-500], the weight of the epoxy resin accounts for 1-15% of the total weight of the resin composition, and the CTE 2 is significantly reduced by using the CTE reducing auxiliary agent; and the condition of CTE mismatch or overlarge stress of each material interface is obviously improved in reliability assessment. The epoxy resin is used and the epoxy equivalent of the epoxy resin is set. Compared with the epoxy equivalent range of 100-300 of the common epoxy resin in the field, the epoxy equivalent of the given epoxy resin is [207-221] and [450-500], when the epoxy equivalent is large, the reaction is slow, the wetting dispersibility is good, the bonding force of each interface is improved, and the reliability is facilitated.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, in particular to a resin composition and a preparation method thereof. Background Art

[0002] Epoxy resin compositions are thermosetting materials widely used in electronic packaging. They not only protect chips from external environmental influences, particularly mechanical and physical forces (such as impact and pressure) and chemical forces (such as moisture, heat, and ultraviolet light), but also provide a heat dissipation path for the chips. They are primarily used to encapsulate and protect semiconductor devices such as diodes, power devices, and large-scale / ultra-large-scale integrated circuit (LSI) packaging.

[0003] With the development of new energy vehicle technology, the performance requirements for on-board modules (such as silicon carbide modules) are getting higher and higher, and the corresponding power density, power cycle reliability, and surge current capability are required to be higher. The corresponding module packaging materials (resin compositions) have more stringent requirements in terms of reliability assessment. Not only is it required that the plastic packaging materials and internal chips and various components have no delamination, but also that thermal shock (TS), high temperature and high humidity reverse bias aging test (H3TRB) / highly accelerated temperature and humidity stress test (HAST), high temperature reverse bias test (HTRB) / high temperature gate bias test (HTGB), high temperature storage (HTS) / low temperature storage (LTS), vibration / impact and other assessment tests are carried out to ensure that the internal components can operate normally and stably for a long time under extreme environments.

[0004] TS failure occurs when a product experiences drastic temperature fluctuations, leading to functional loss, performance degradation, or structural damage due to factors such as material properties, structural design, and manufacturing processes. Three main reasons for epoxy molding compound (EMC) failure during TS testing are: First, thermal expansion coefficient mismatch. When different materials undergo thermal shock, the expansion or contraction of the component generates varying degrees of thermal stress, exceeding the material's tolerance limit and causing failure. Second, insufficient material toughness. During thermal shock cycles, cracks easily form and gradually propagate, leading to failure. Third, rapid temperature fluctuations prevent the material from expanding or contracting uniformly, generating significant transient thermal stress and increasing the risk of failure. To address these failure risks, the encapsulant material must have a high Tg, a maximum TS temperature below the glass transition temperature, minimal CTE change (expansion or contraction) during temperature fluctuations, and low stress to maintain sufficient material toughness and minimize stress fluctuations during high and low temperature fluctuations.

[0005] The existing technical solution is to obtain a high Tg molding material by selecting an epoxy resin or a phenolic resin having a multifunctional structure, and to add a large amount of stress release agent to reduce the stress of the material.

[0006] The drawbacks of this technical solution are that, although the molding compound has a high Tg, it suffers from poor adhesion, high stress, and poor reliability. Furthermore, a large amount of stress release agent not only increases water absorption but also easily causes mold sticking and dirtying, resulting in poor continuous molding processability. To address this issue, a resin composition and a method for preparing the same are provided. Summary of the Invention

[0007] The purpose of the present invention is to provide a resin composition and a preparation method thereof in view of the defects of the prior art, so as to solve the problems raised by the above background technology.

[0008] To achieve the above object, the present invention provides the following technical solution: a resin composition comprising an epoxy resin, a curing agent, a curing accelerator, a filler, a coupling agent, and a CTE-reducing agent;

[0009] The epoxy equivalent weight of the epoxy resin is [207-221] and [450-500], and the weight of the epoxy resin accounts for 1-15% of the total weight of the resin composition. The structure of the epoxy resin is shown in formula (1):

[0010]

[0011] Wherein, A / B is any one of -H, -CH3, -CH2CH3, -C(CH3)3, -OCH2CHOCH2;

[0012] X is Any of;

[0013] The curing agent is a phenolic resin, and the weight of the curing agent accounts for 1-15% of the total weight of the resin composition;

[0014] The weight of the filler accounts for 75-92% of the total weight of the resin composition;

[0015] The weight of the curing accelerator accounts for 0.01-2% of the total weight of the resin composition;

[0016] The weight of the coupling agent accounts for 0.1-2% of the total weight of the resin composition;

[0017] The CTE lowering agent is any one of polyester polyol, silicone resin, acrylate resin and polybutadiene, and the weight of the CTE lowering agent accounts for 0.2-5% of the total weight of the resin composition.

[0018] As a preferred technical solution of the present invention, the CTE-reducing auxiliary agent is polyester polyol.

[0019] As a preferred technical solution of the present invention, the ratio of the epoxy equivalent in the epoxy resin to the hydroxyl equivalent in the phenolic resin is 0.5-1.5.

[0020] As a preferred technical solution of the present invention, the epoxy resin accounts for 2-10% of the total weight of the resin composition.

[0021] As a preferred technical solution of the present invention, the curing agent accounts for 2-10% of the total weight of the resin composition.

[0022] As a preferred technical solution of the present invention, the glass transition temperature of the CTE-reducing additive is less than 100°C.

[0023] As a preferred technical solution of the present invention, the glass transition temperature of the CTE-reducing additive is less than 70°C.

[0024] A method for preparing the resin composition as described above, comprising the following specific steps:

[0025] Step 1: Pre-dispersion reaction of CTE-reducing additive:

[0026] At room temperature, add the measured phenolic resin to the reactor, heat it until the phenolic resin is completely melted, and after the material temperature stabilizes, add the CTE lowering agent, continue heating and stirring until the CTE lowering agent is evenly dispersed in the resin, continue heating for 10-60 minutes until the mixture is completely uniform and the material viscosity is stable; cool it down, discharge it, crush it after cooling, and refrigerate it in a sealed bag for later use;

[0027] Step 2: Pre-dispersion cross-linking reaction of epoxy resin:

[0028] At room temperature, the measured phenolic resin is added to the reactor, and the temperature is raised until the phenolic resin is completely melted. After the material temperature stabilizes, an epoxy resin with an epoxy equivalent of [450-500] is added according to the ratio. The ratio of epoxy group to phenolic group is less than 0.5 to ensure that the phenolic resin is sufficiently excessive. The mixture is heated for 10-60 minutes until it is completely uniformly mixed and the viscosity of the material is stable. The mixture is cooled, discharged, crushed after cooling, and refrigerated in a sealed bag for later use.

[0029] Step 3: Preparation of resin composition:

[0030] The inorganic filler and other inorganic additives in the formula are placed in a high-speed mixer for stirring. The speed and stirring time are set as needed to ensure uniform stirring. Then, the pre-dispersed CTE additive and the pre-dispersed cross-linked epoxy resin and the remaining epoxy resin and phenolic resin are added and stirred evenly. Then, other coupling agents and liquid additives are added. After continuing to stir until uniform, the mixture is placed in an extruder, hot roller or kneader for kneading and calendering. Then, the mixture is cooled and crushed to a suitable particle size to obtain a powdered resin composition.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] 1. The present invention significantly reduces CTE2 by using a CTE-reducing additive; the CTE mismatch or excessive stress at each material interface in reliability assessment is significantly improved.

[0033] 2. The present invention uses an epoxy resin having a structure of formula (1) and sets the epoxy equivalent of the epoxy resin. Compared with the epoxy equivalent range of 100-300 of epoxy resins commonly used in the field, the present invention provides epoxy resins with epoxy equivalents of [207-221] and [450-500]. When the epoxy equivalent is larger, the reaction is slower, the wetting and dispersibility are good, the adhesion of each interface is improved, and reliability is helpful; at the same time, when the epoxy equivalent is large, there are generally fewer epoxy groups (epoxy equivalent is the mass of epoxy resin with one mole of epoxy groups in grams, epoxy equivalent = 100 / epoxy value, which is inversely proportional to the epoxy value. When the epoxy equivalent is large, there are fewer epoxy groups), and the interior generally has flexible chain segments to reduce the overall stress level; when the epoxy equivalent is too large, such as >1000, it is generally used as an auxiliary agent and does not participate in the cross-linking reaction, which is prone to overflow, dirty mold, and sticking to the mold; while within 600, it can be used directly as a resin, participate in the cross-linking reaction, reduce stress without affecting continuous moldability. DETAILED DESCRIPTION

[0034] The preferred embodiments of the present invention are described in detail below so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more precise definition of the protection scope of the present invention.

[0035] The existing technical solution is to obtain a high Tg molding material by selecting an epoxy resin or a phenolic resin having a multifunctional structure, and to add a large amount of stress release agent to reduce the stress of the material.

[0036] The drawbacks of this solution are: although the molding compound has a high Tg, it suffers from poor adhesion, high stress, and poor reliability. Furthermore, a large amount of stress release agent not only increases water absorption but also easily causes mold sticking and dirtiness, resulting in poor continuous mold processing performance.

[0037] Therefore, one of the objects of the present invention is to provide a resin composition comprising an epoxy resin, a curing agent, a curing accelerator, a filler, a coupling agent, and a CTE reducing agent;

[0038] The epoxy equivalent weight of the epoxy resin is [207-221] and [450-500], and the weight of the epoxy resin accounts for 1-15% of the total weight of the resin composition, preferably 2-10%. The structure of the epoxy resin is shown in formula (1):

[0039]

[0040] Wherein, A / B is any one of -H, -CH3, -CH2CH3, -C(CH3)3, -OCH2CHOCH2;

[0041] X is Any of;

[0042] The curing agent is a phenolic resin, and the weight of the curing agent accounts for 1-15% of the total weight of the resin composition, preferably 2-10%;

[0043] The weight of the filler accounts for 75-92% of the total weight of the resin composition;

[0044] The weight of the curing accelerator accounts for 0.01-2% of the total weight of the resin composition;

[0045] The weight of the coupling agent accounts for 0.1-2% of the total weight of the resin composition;

[0046] The CTE lowering agent is any one of polyester polyol, silicone resin, acrylate resin and polybutadiene, and the weight of the CTE lowering agent accounts for 0.2-5% of the total weight of the resin composition.

[0047] The CTE lowering agent is polyester polyol; the ratio of epoxy equivalent in epoxy resin to hydroxyl equivalent in phenolic resin is 0.5-1.5;

[0048] The glass transition temperature of the CTE-reducing additive is less than 100°C, preferably less than 70°C.

[0049] Without affecting the effect of the present invention, the curing agent can be a curing agent of the phenolic resin type commonly used in the art, for example: phenol·aralkyl resin, biphenyl-type phenol·aralkyl resin, naphthol·aralkyl resin, etc. synthesized by reacting phenols and / or naphthols such as phenol, cresol, resorcinol, catechol, bisphenol A, bisphenol F, phenylphenol, aminophenol, and dimethoxy-p-xylene or bis(methoxymethyl)biphenyl; dicyclopentadiene-type phenolic resins such as dicyclopentadiene-type phenolic novolac-type epoxy resin and dicyclopentadiene-type naphthol phenolic novolac-type epoxy resin synthesized by copolymerizing phenols and / or naphthols with dicyclopentadiene; triphenylmethane-type phenolic resin; terpene-modified phenolic resin; p-xylene and / or m-xylene-modified phenolic resin; melamine-modified phenolic resin; cyclopentadiene-type modified phenolic phenolic resin; and phenolic resins obtained by copolymerizing two or more of them, etc.

[0050] There are no special requirements for the curing agent accelerator; any known curing agent accelerator used in resin compositions can be used. Commonly used tertiary amine compounds; imidazole compounds, including 2-methylimidazole, 2-phenylimidazole, 2-methyl-4-ethylimidazole, etc.; quaternary ammonium salts; organic metal salts; phosphorus compounds, such as triphenylphosphine, tributylphosphine, adducts of triphenylphosphine and benzoquinone, tetraphenylboric acid, tetraphenylphosphine, triphenylphosphine triphenylborane, etc.; diazacycloolefins, etc., these compounds and their derivatives can be used alone or in combination. The content of the curing agent accelerator is 0.01-2% of the total weight of the epoxy resin.

[0051] Inorganic fillers are the filling components in epoxy resin compositions. Any known inorganic filler used in epoxy resins in prior art solutions can be used, such as fused silica, crystalline silica, alumina, aluminum nitride, and boron nitride. Spherical and fused silica with an average particle size of 3-30 microns are preferred inorganic fillers. The inorganic filler accounts for 75-92% of the total weight of the resin composition, preferably 80-89% depending on specific requirements such as warpage and CTE.

[0052] The CTE-reducing agent can be polyester resin, silicone resin, acrylate resin, or polybutadiene. The content of the CTE-reducing agent accounts for 0.2-5% of the total weight of the resin composition.

[0053] Coupling agent: To enhance the bonding strength between the inorganic filler and the resin, silane coupling agents or titanate coupling agents known in the art can be used. Examples include γ-epoxypropyltrimethoxysilane, γ-epoxypropyltriethoxysilane, γ-ureidopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, N-phenylγ-aminopropyltrimethoxysilane, and γ-isocyanatepropyltriethoxysilane, which can be used alone or in combination. The coupling agent content is 0-5% by weight of the total resin composition.

[0054] Other additives: In addition to the above components, various additives may also be included if necessary, such as release agents, colorants (such as carbon black, titanium oxide, red iron oxide, etc.), ion capture agents, etc.

[0055] The resin composition of the present invention is not particularly limited to the release agent. Natural or synthetic waxes known in the art may be used as the release agent. Examples include carnauba wax, polyethylene wax, montan wax, rice wax, saponified montan wax, stearic acid, stearate esters, and zinc stearate. The release agent may constitute 0-5% of the total weight of the resin composition.

[0056] The resin composition of the present invention may further include flame retardants such as aluminum hydroxide, magnesium hydroxide, zinc borate, zinc molybdate, melamine, etc. in addition to the above components, if necessary, to achieve an environmentally friendly flame retardant effect.

[0057] The second object of the present invention is to provide a method for preparing the resin composition as described above, the specific steps are as follows:

[0058] Step 1: Pre-dispersion reaction of CTE-reducing additive:

[0059] At room temperature, the measured phenolic resin is added to a reactor, and the temperature is raised until the phenolic resin is completely melted. After the material temperature stabilizes, a CTE-reducing agent is added, and heating and stirring are continued until the CTE agent is evenly dispersed in the resin. Heating is continued for 10-60 minutes until the mixture is completely and evenly mixed and the material viscosity stabilizes. The temperature is lowered, the material is discharged, and after cooling, it is crushed and refrigerated in a sealed bag for later use. The mass ratio of phenolic resin to CTE agent is 1:1. The principle is that the two are mixed evenly at high temperature and can be well crushed without delamination after cooling to room temperature.

[0060] Step 2: Pre-dispersion cross-linking reaction of epoxy resin:

[0061] At room temperature, remove the phenolic resin used in step 1, and add the remaining phenolic resin in the formula into the reactor, heat it until the phenolic resin is completely melted, and after the material temperature stabilizes, add epoxy resin with an epoxy equivalent of [450-500] according to the ratio;

[0062] According to the ratio of epoxy group to phenolic group, the ratio is less than 0.5 to ensure that the phenolic group is sufficiently excessive. Continue heating for 10-60 minutes until it is completely uniformly mixed and the viscosity of the material is stable. Cool down, discharge the material, crush it after cooling, and refrigerate it in a sealed bag for later use.

[0063] Step 3, preparation of resin composition:

[0064] The inorganic filler and other inorganic additives in the formula are placed in a high-speed mixer for stirring. The speed and stirring time are set as needed to ensure uniform stirring. Then, the pre-dispersed CTE additive and the pre-dispersed cross-linked epoxy resin and the remaining epoxy resin and phenolic resin are added and stirred evenly. Then, other coupling agents and liquid additives are added. After continuing to stir until uniform, the mixture is placed in an extruder, hot roller or kneader for kneading and calendering. Then, the mixture is cooled and crushed to a suitable particle size to obtain a powdered resin composition.

[0065] The resin composition and preparation method thereof provided by the present invention are further described through the following specific examples.

[0066] A resin composition comprising an epoxy resin, a curing agent, a curing accelerator, a filler, a coupling agent, and a CTE reducing agent;

[0067] Epoxy resin A: Epoxy resin FAE-2500, epoxy equivalent weight 214 (epoxy equivalent weight is the value measured by hydrochloric acid acetone method), purchased from Nippon Kayaku, where A is -C(CH3)3, B is -CH3, and X is

[0068] Epoxy resin B: Epoxy resin EPCYD-011, epoxy equivalent weight 475 (epoxy equivalent weight is the value measured by hydrochloric acid acetone method), purchased from Baling Petrochemical, where A / B in formula (1) are both -H, and X is

[0069]

[0070] Epoxy resin M1: Epoxy resin is EPPN-501HY, with an epoxy equivalent weight of 161, purchased from Nippon Kayaku. Its structure is the same as that shown in formula (1); wherein A / B are both -H, X is

[0071] Epoxy resin M2: epoxidized hydroxy-terminated polybutadiene (EHTPB2023-L-190809), epoxy equivalent weight 1100, purchased from Liming Chemical;

[0072] Curing agent C1: phenolic resin is MEH 7500, purchased from Meiwa Plastics Ind., Ltd.

[0073] Curing accelerator D: 2,4-diamino-6-[2-(2-methyl-1-imidazolyl)ethyl]-1,3,5-thiazine (C11Z-A), purchased from Shikoku Chemical;

[0074] Silica powder E: NQ1140D, purchased from Jiangsu Lianrui New Materials Co., Ltd.

[0075] CTE-lowering additive F: FPS600, polyester polyol, purchased from DIC;

[0076] Coupling agent G: anilino-n-propyltrimethoxysilane, purchased from Momentive;

[0077] Release agent H: wax, purchased from Clariant;

[0078] Colorant: Carbon black I: JY 2021, purchased from Sichuan Zhenghao;

[0079] The epoxy resin composition prepared in this experiment was used for relevant testing tests:

[0080] Gel time (GT): Gel time (s) is measured according to Section 6.1 Gel time of GB / T 40564-2021 Test method for epoxy molding compounds for electronic packaging.

[0081] Flow length (SF): The flow distance (cm) is measured according to the spiral flow length in Section 6.2 of GB / T 40564-2021 Test Method for Epoxy Molding Compounds for Electronic Packaging.

[0082] Glass transition temperature: Tested according to the dynamic mechanical analyzer (DMA) method (bending mode) in accordance with Section 6.8.1 of GB / T 40564-2021 Test Methods for Epoxy Molding Compounds for Electronic Packaging, and the Tan Delta peak value is taken as Tg.

[0083] Linear expansion coefficient: According to the linear expansion coefficient test in Article 6.9 of GB / T 40564-2021 Test method for epoxy molding compounds for electronic packaging, the linear expansion coefficient below the Tg point (CTE1) and above the Tg point (CTE2) are taken.

[0084] CTE is the coefficient of thermal expansion. The thermal expansion coefficients of epoxy resin compositions vary greatly before and after the glass transition temperature. CTE1 is the thermal expansion coefficient at low temperatures before the glass transition temperature (e.g., 20°C-60°C), and CTE2 is the thermal expansion coefficient at high temperatures after the glass transition temperature (e.g., 220°C-240°C).

[0085] Water absorption: The water absorption test shall be conducted in accordance with GB / T 40564-2021 Test methods for epoxy molding compounds for electronic packaging, clause 6.10 Water absorption.

[0086] Operability Test: Epoxy resin powder is prepared into cakes of specified specifications based on customer requirements. SiC automotive components are then molded and encapsulated under conditions of a clamping pressure of 160 kgf / cm², an injection pressure of 80 kgf / cm², a molding temperature of 175°C, and a curing time of 180 seconds. Operability is considered acceptable if the encapsulation is free of pores, blisters, or sticking film. Otherwise, it is considered NG.

[0087] Reliability testing: Epoxy resin powder is prepared into cakes of specified specifications based on customer specifications. The SiC automotive device is then encapsulated using a mold clamping pressure of 160 kgf / cm², an injection pressure of 80 kgf / cm², a molding temperature of 175°C, and a curing time of 180 seconds. The encapsulated SiC automotive device is then post-cured at 175°C for 6 hours. Reliability testing includes 1000 cycles of high and low temperature shock (TS) testing (-40°C to 150°C), LTS (-40°C, 1000 hours) / HTS (125°C, 1000 hours), HTRB / HTGB (175°C, ≥1000 hours), and H3TRB (85°C, 85% humidity, ≥1000 hours) / HAST testing. TS testing is performed only if there is no delamination between the encapsulating compound and other materials. Otherwise, the product is considered NG.

[0088] Example 1: A resin composition comprising epoxy resin A, epoxy resin B, curing agent C, curing accelerator D, silica powder E, CTE lowering agent F, coupling agent G, release agent H, and colorant I; the specific formula is as shown in the following table; the specific preparation method is as follows:

[0089] Step 1: Pre-dispersion reaction of the CTE-lowering agent (Intermediate 1): At room temperature, 2.2 kg of the measured curing agent C1 (phenolic resin MEH7500) was added to a reactor set to 150°C. The temperature was raised until the phenolic resin was completely melted. After the temperature stabilized, 2.2 kg of the CTE-lowering agent FPS600 was added. Heating and stirring were continued for 40 minutes until completely uniformly mixed and the viscosity of the material stabilized. The temperature was then lowered to 120°C. Once the temperature stabilized, the material was discharged, cooled, crushed, and refrigerated in a sealed bag for later use.

[0090] Step 2: Pre-dispersion cross-linking reaction of epoxy resin (intermediate 2): At room temperature, 1.6 kg of the measured curing agent C1 (phenolic resin MEH7500) was added to a reactor set at 150°C. The temperature was raised until the phenolic resin was completely melted. After the material temperature stabilized, 12 kg of epoxy resin B EPCYD-01 was added, with an E / OH ratio of 0.26 between the epoxy group and the phenolic group. Heating was continued for 40 minutes until completely uniformly mixed and the material viscosity stabilized. The temperature was then lowered to 120°C, the material was discharged, pulverized after cooling, and refrigerated in a sealed bag for later use.

[0091] Step 3: Preparation of resin composition:

[0092] According to the formula ratio, first add silicon powder E and colorant I, put into a high-speed mixer and stir for 5 minutes, then add intermediate 1, intermediate 2, epoxy resin A, release agent H, and curing accelerator D and stir for 5 minutes, finally add coupling agent G, continue stirring for 15 minutes until uniform, put into a twin-screw extruder for kneading and calendering, and then cool and crush to a suitable particle size to obtain a powdered resin composition.

[0093] Example 2: A resin composition comprising epoxy resin A, epoxy resin B, curing agent C, curing accelerator D, silica powder E, CTE lowering agent F, coupling agent G, release agent H, and colorant I; the specific formula is shown in the following table; the specific preparation method is as follows:

[0094] Step 1: Pre-dispersion Reaction of the CTE-Lowering Agent (Intermediate 1): At room temperature, 2.6 kg of the measured curing agent C1 (phenolic resin MEH7500) was added to a reactor set to 150°C. The temperature was raised until the phenolic resin was completely melted. After the temperature stabilized, 2.2 kg of the CTE-lowering agent FPS600 was added. Heating and stirring were continued for 40 minutes until the mixture was completely uniformly mixed and the viscosity of the material stabilized. The temperature was then lowered to 120°C. Once the temperature stabilized, the material was discharged, cooled, crushed, and refrigerated in a sealed bag for later use.

[0095] Step 2: Pre-dispersion cross-linking reaction of epoxy resin (intermediate 2): At room temperature, 1.6 kg of the measured curing agent C1 (phenolic resin MEH7500) was added to a reactor set at 150°C. The temperature was raised until the phenolic resin was completely melted. After the material temperature stabilized, 12 kg of epoxy resin B EPCYD-01 was added, with an E / OH ratio of 0.26 between the epoxy group and the phenolic group. Heating was continued for 40 minutes until completely uniformly mixed and the material viscosity stabilized. The temperature was then lowered to 120°C, the material was discharged, pulverized after cooling, and refrigerated in a sealed bag for later use.

[0096] Step 3: Preparation of resin composition:

[0097] According to the formula ratio, first add silicon powder E and colorant I, put into a high-speed mixer and stir for 5 minutes, then add intermediate 1, intermediate 2, epoxy resin A, release agent H, and curing accelerator D and stir for 5 minutes, finally add coupling agent G, continue stirring for 15 minutes until uniform, put into a twin-screw extruder for kneading and calendering, and then cool and crush to a suitable particle size to obtain a powdered resin composition.

[0098] Comparative Examples are as follows:

[0099] Comparative Example 1: Based on Example 1, epoxy resin A was replaced with an epoxy resin (epoxy resin M1) with a small epoxy equivalent weight (epoxy equivalent weight 161); the specific formula is shown in the following table; the specific preparation method adopts the preparation method of the present invention.

[0100] Step 1: Pre-dispersion reaction of the CTE-lowering agent (Intermediate 1): At room temperature, 2.2 kg of the measured curing agent C1 (phenolic resin MEH7500) was added to a reactor set to 150°C. The temperature was raised until the phenolic resin was completely melted. After the temperature stabilized, 2.2 kg of the CTE-lowering agent FPS600 was added. Heating and stirring were continued for 40 minutes until completely uniformly mixed and the viscosity of the material stabilized. The temperature was then lowered to 120°C. Once the temperature stabilized, the material was discharged, cooled, crushed, and refrigerated in a sealed bag for later use.

[0101] Step 2: Pre-dispersion cross-linking reaction of epoxy resin (intermediate 2): At room temperature, 1.6 kg of the measured curing agent C1 (phenolic resin MEH7500) was added to a reactor set at 150°C. The temperature was raised until the phenolic resin was completely melted. After the material temperature stabilized, 12 kg of epoxy resin B EPCYD-01 was added, with an E / OH ratio of 0.26 between the epoxy group and the phenolic group. Heating was continued for 40 minutes until completely uniformly mixed and the material viscosity stabilized. The temperature was then lowered to 120°C, the material was discharged, pulverized after cooling, and refrigerated in a sealed bag for later use.

[0102] Step 3: Preparation of resin composition:

[0103] According to the formula ratio, first add silicon powder E and colorant I, put into a high-speed mixer and stir for 5 minutes, then add intermediate 1, intermediate 2, epoxy resin M1, release agent H, and curing accelerator D and stir for 5 minutes, and finally add coupling agent G. Continue stirring for 15 minutes until uniform, put into a twin-screw extruder for kneading and calendering, and then cool and crush to a suitable particle size to obtain a powdered resin composition.

[0104] Comparative Example 2: Based on Example 1, epoxy resin B was replaced with resin M2 having a large epoxy equivalent (epoxy equivalent 1100). The specific formula is shown in the following table. The specific preparation method adopts the preparation method of the present invention.

[0105] Step 1: Pre-dispersion reaction of the CTE-lowering agent (Intermediate 1): At room temperature, 2.2 kg of the measured curing agent C1 (phenolic resin MEH7500) was added to a reactor set to 150°C. The temperature was raised until the phenolic resin was completely melted. After the temperature stabilized, 2.2 kg of the CTE-lowering agent FPS600 was added. Heating and stirring were continued for 40 minutes until completely uniformly mixed and the viscosity of the material stabilized. The temperature was then lowered to 120°C. Once the temperature stabilized, the material was discharged, cooled, crushed, and refrigerated in a sealed bag for later use.

[0106] Step 2: Pre-dispersion cross-linking reaction of epoxy resin (intermediate 2): At room temperature, 1.6 kg of the measured curing agent C1 (phenolic resin MEH7500) was added to a reactor. The reactor was set to a temperature of 150°C and heated until the phenolic resin was completely melted. After the material temperature stabilized, 22 kg of epoxy resin M was added, with an E / OH ratio of 0.12 between epoxy groups and phenolic groups. Heating was continued for 40 minutes until completely uniformly mixed and the material viscosity was stable; the temperature was lowered by 120°C, the material was discharged, crushed after cooling, and refrigerated in a sealed bag for later use;

[0107] Step 3: Preparation of resin composition:

[0108] According to the formula ratio, first add silicon powder E and colorant I, put into a high-speed mixer and stir for 5 minutes, then add intermediate 1, intermediate 2, epoxy resin A, release agent H, and curing accelerator D and stir for 5 minutes, finally add coupling agent G, continue stirring for 15 minutes until uniform, put into a twin-screw extruder for kneading and calendering, and then cool and crush to a suitable particle size to obtain a powdered resin composition.

[0109] Comparative Example 3: Based on Example 2, the CTE-lowering agent was removed, and the removed portion was added to epoxy resin A / B, curing agent C1, and curing accelerator D in proportion. The specific formula is shown in the table below. The specific preparation method adopts the preparation method of the present invention.

[0110] Step 1: Pre-dispersion cross-linking reaction of epoxy resin (intermediate 2): At room temperature, 5 kg of the measured curing agent C1 (phenolic resin MEH7500) was added to a reactor set at 150°C. The temperature was raised until the phenolic resin was completely melted. After the material temperature stabilized, 3.55 kg of epoxy resin B EPCYD-011 was added, with an E / OH ratio of 0.15 between the epoxy group and the phenolic group. Heating was continued for 30 minutes until completely mixed and the material viscosity stabilized. The temperature was then lowered to 120°C, the material was discharged, pulverized after cooling, and refrigerated in a sealed bag for later use.

[0111] Step 2: Preparation of resin composition:

[0112] According to the formula ratio, first add silicon powder E and colorant I, put them into a high-speed mixer and stir for 5 minutes, then add intermediate 2, epoxy resin A, release agent H, and curing accelerator D and stir for 5 minutes, and finally add coupling agent G. Continue stirring for 15 minutes until uniform, put them into a twin-screw extruder for kneading and calendering, and then cool and crush to a suitable particle size to obtain a powdered resin composition.

[0113]

[0114] The above embodiments merely illustrate the implementation methods of the present invention. Although the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that a person skilled in the art may make various modifications and improvements without departing from the scope of the present invention, and these modifications and improvements fall within the scope of protection of the present invention.

Claims

1. A resin composition, characterized in that: Including epoxy resin, curing agent, curing accelerator, filler, coupling agent, CTE reducing agent; The epoxy equivalent weight of the epoxy resin is [207-221] and [450-500], and the weight of the epoxy resin accounts for 1-15% of the total weight of the resin composition. The structure of the epoxy resin is shown in formula (1): Wherein, A / B is any one of -H, -CH3, -CH2CH3, -C(CH3)3, -OCH2CHOCH2; X is Any of; The curing agent is a phenolic resin, and the weight of the curing agent accounts for 1-15% of the total weight of the resin composition; The weight of the filler accounts for 75-92% of the total weight of the resin composition; The weight of the curing accelerator accounts for 0.01-2% of the total weight of the resin composition; The weight of the coupling agent accounts for 0.1-2% of the total weight of the resin composition; The CTE lowering agent is any one of polyester polyol, silicone resin, acrylate resin and polybutadiene, and the weight of the CTE lowering agent accounts for 0.2-5% of the total weight of the resin composition.

2. The resin composition according to claim 1, wherein: The CTE lowering agent is polyester polyol.

3. The resin composition according to claim 1, wherein: The ratio of the epoxy equivalent in the epoxy resin to the hydroxyl equivalent in the phenolic resin is 0.5-1.

5.

4. The resin composition according to claim 1, wherein: The epoxy resin accounts for 2-10% of the total weight of the resin composition.

5. The resin composition according to claim 1, wherein: The curing agent accounts for 2-10% of the total weight of the resin composition.

6. The resin composition according to claim 1, wherein: The CTE-reducing additive has a glass transition temperature of less than 100°C.

7. The resin composition according to claim 6, wherein: The CTE-reducing additive has a glass transition temperature of less than 70°C.

8. A method for preparing the resin composition according to any one of claims 1 to 7, characterized in that: The specific steps are as follows: Step 1: Pre-dispersion reaction of CTE-reducing additive: At room temperature, add the measured phenolic resin to the reactor, heat it until the phenolic resin is completely melted, and after the material temperature stabilizes, add the CTE lowering agent, continue heating and stirring until the CTE lowering agent is evenly dispersed in the resin, continue heating for 10-60 minutes until the mixture is completely uniform and the material viscosity is stable; cool it down, discharge it, crush it after cooling, and refrigerate it in a sealed bag for later use; Step 2: Pre-dispersion cross-linking reaction of epoxy resin: At room temperature, the measured phenolic resin is added to the reactor, and the temperature is raised until the phenolic resin is completely melted. After the material temperature stabilizes, an epoxy resin with an epoxy equivalent of [450-500] is added according to the ratio. The ratio of epoxy group to phenolic group is less than 0.5 to ensure that the phenolic resin is sufficiently excessive. The mixture is heated for 10-60 minutes until it is completely uniformly mixed and the viscosity of the material is stable. The mixture is cooled, discharged, crushed after cooling, and refrigerated in a sealed bag for later use. Step 3: Preparation of resin composition: The inorganic filler and other inorganic additives in the formula are placed in a high-speed mixer for stirring. The speed and stirring time are set as needed to ensure uniform stirring. Then, the pre-dispersed CTE additive and the pre-dispersed cross-linked epoxy resin and the remaining epoxy resin and phenolic resin are added and stirred evenly. Then, other coupling agents and liquid additives are added. After continuing to stir until uniform, the mixture is placed in an extruder, hot roller or kneader for kneading and calendering. Then, the mixture is cooled and crushed to a suitable particle size to obtain a powdered resin composition.

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