Epoxy molding compound and preparation method and application thereof
By introducing cashew phenol-terminated isocyanate as a modifier into epoxy molding compound, the problem of high internal stress in traditional epoxy molding compounds is solved, and the low stress and heat resistance properties are improved, making it suitable for packaging high-density, miniaturized electronic devices.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-29
- Publication Date
- 2026-03-27
AI Technical Summary
Traditional epoxy molding compounds are prone to generating high internal stress during the curing process, which can lead to problems such as warping, cracking, pin peeling, and delamination in encapsulated electronic components. The failure rate is particularly high in the encapsulation of precision electronic devices. Existing modifiers have problems with poor compatibility with epoxy resins and poor heat resistance.
Cashew phenol-terminated isocyanate was used as a low-stress modifier and mixed with epoxy resin, phenolic resin and other components. Through melt mixing and melt compounding processes, an epoxy molding compound with good compatibility was prepared, which reduced the crosslinking density and introduced flexible long chains to improve the system's flexibility.
It achieves low-stress characteristics and excellent heat resistance of epoxy molding compounds, reduces the coefficient of linear expansion and flexural modulus, and ensures the stability of mechanical and electrical properties, making it suitable for packaging high-density, miniaturized electronic devices.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of electronic packaging technology, specifically to an epoxy molding compound, its preparation method, and its application. Background Technology
[0002] Epoxy molding compounds are widely used in the packaging processes of electronic components such as integrated circuits and semiconductor devices due to their excellent adhesion, insulation, resistance to damp heat, and processing fluidity. Their performance directly affects the stability and lifespan of electronic components. However, traditional epoxy molding compounds are prone to generating high internal stress during the curing process. This is mainly due to factors such as volume shrinkage during the reaction between epoxy resin and curing agent, and the mismatch of thermal expansion coefficients of various components. These internal stresses can lead to problems such as warping, cracking, lead peeling, and delamination in packaged electronic components. Especially in the packaging of precision electronic devices, the failure rate caused by internal stress increases significantly, severely restricting the application of epoxy molding compounds in high-end electronics fields.
[0003] To reduce the internal stress of epoxy molding compounds, existing technologies typically employ the addition of flexible modifiers, such as carboxyl-terminated nitrile rubber, polysiloxanes, and polyurethanes. However, these traditional modifiers have several drawbacks: carboxyl-terminated nitrile rubber has poor compatibility with epoxy resins, easily leading to a decline in the mechanical and electrical properties of the molding compound; polysiloxanes are expensive and have weak interfacial bonding with the system, affecting the overall performance of the molding compound; and polyurethane modifiers have poor heat resistance, making it difficult to meet the requirements of high-temperature encapsulation processes. Therefore, developing a novel modifier with good compatibility with epoxy resins, excellent heat resistance, and the ability to effectively reduce the internal stress of molding compounds is of great significance for the preparation of high-performance, low-stress epoxy molding compounds. Summary of the Invention
[0004] The purpose of this invention is to overcome the problems of poor compatibility with epoxy resin, poor heat resistance, and difficulty in effectively reducing the internal stress of the molding compound when using flexible modifiers in the prior art. This invention provides an epoxy molding compound, its preparation method, and its application. The epoxy molding compound uses cashew phenol-terminated isocyanate as a low-stress modifier, exhibiting excellent heat resistance and low-stress characteristics, and has good compatibility with epoxy resin.
[0005] To achieve the above objectives, the present invention provides an epoxy molding compound comprising epoxy resin, phenolic resin, solid filler, accelerator, ion trapping agent, low-stress modifier, coupling agent, release agent, and colorant. Based on a total mass of 100 parts of the epoxy molding compound, the contents of the epoxy resin, phenolic resin, solid filler, accelerator, ion trapping agent, low-stress modifier, coupling agent, release agent, and colorant are 1-30 parts, 1-30 parts, 60-90 parts, 0.01-2 parts, 0.1-1 parts, 0.1-1 parts, 0.1-1 parts, 0.1-1 parts, 0.1-1 parts, and 0.1-1 parts, respectively; wherein the low-stress modifier is cashew phenol-terminated isocyanate.
[0006] Preferably, the epoxy resin is selected from at least one of o-cresol epoxy resin, biphenyl epoxy resin, aralkyl epoxy resin, ester ring epoxy resin, heterocyclic epoxy resin, bisphenol A epoxy resin, bisphenol F epoxy resin, dicyclopentadiene epoxy resin, naphthalene ring epoxy resin, and multifunctional epoxy resin.
[0007] Preferably, the epoxy resin is selected from at least one of biphenyl-type epoxy resin, naphthalene-type epoxy resin, and o-cresol epoxy resin.
[0008] Preferably, the phenolic resin is selected from at least one of linear phenolic resin, biphenyl-type phenolic resin, naphthalene-type phenolic resin, arylalkylphenol-type phenolic resin, and multifunctional phenolic resin.
[0009] Preferably, the phenolic resin is selected from at least one of linear phenolic resin, biphenyl-type phenolic resin, and multifunctional phenolic resin.
[0010] Preferably, the solid filler is selected from at least one of fused silica powder, crystalline silica powder, alumina, and aluminum nitride.
[0011] Preferably, the solid filler is fused silica powder.
[0012] Preferably, the particle size of the solid filler is 0.5~100μm, and more preferably, the median particle size of the solid filler is 10~30μm.
[0013] Preferably, the accelerator is selected from at least one of imidazole accelerators, organophosphorus accelerators, and tertiary amine accelerators.
[0014] Preferably, the imidazole accelerator is selected from at least one of 2-methylimidazole, 2-ethyl-4-methylimidazole and 1-benzyl-2-methylimidazole.
[0015] Preferably, the organophosphorus accelerator is a triphenylphosphine-benzoquinone adduct and / or a tetraphenylphosphine salt.
[0016] Preferably, the accelerator is a triphenylphosphine-benzoquinone adduct.
[0017] Preferably, the release agent is selected from at least one of stearic acid, zinc stearate, calcium stearate, oxidized polyethylene wax, and carnauba wax.
[0018] Preferably, the release agent is oxidized polyethylene wax.
[0019] Preferably, the ion scavenging agent is a hydrotalcite compound.
[0020] Preferably, the ion-scavenging agent is hydrotalcite.
[0021] Preferably, the coupling agent is selected from γ-ray dihydropyridine (γ-ray dihydropyridine). glycidyl ether trimethoxysilane, γ aminopropyltriethoxysilane, γ mercaptopropyltrimethoxysilane and γ At least one of glycidyl etheroxypropyltrimethoxysilane.
[0022] Preferably, the coupling agent is γ Glycidyl etheroxypropyltrimethoxysilane.
[0023] Preferably, the colorant is carbon black.
[0024] A second aspect of the present invention provides a method for preparing the above-mentioned epoxy molding compound, the method comprising the following steps: S1. Phenolic resin and low-stress modifier are melt-mixed, and the resulting mixture is made into granules; S2. The granules are mixed with solid fillers, colorants, coupling agents, ion traps, epoxy resins, release agents, and accelerators. The resulting mixture is then melt-mixed, cooled, pulverized, and pre-formed.
[0025] Preferably, the conditions for melting and mixing in step S1 include a temperature of 120~150°C.
[0026] Preferably, the conditions for melt mixing in step S2 include a temperature of 80~120℃.
[0027] A third aspect of the present invention provides an application of the above-mentioned epoxy molding compound in electronic device packaging.
[0028] Through the above technical solution, the epoxy molding compound provided by the present invention has excellent mechanical properties, heat resistance properties, and electrical properties, which can meet the packaging requirements of high-density, miniaturized electronic devices, and specifically achieves the following technical effects: (1) This invention uses cashew phenol-terminated isocyanate as a low-stress modifier. The molecular structure of this low-stress modifier contains flexible long-chain alkyl groups and active isocyanate groups. Under the catalytic action of the accelerator, the cashew phenol-terminated isocyanate can be successfully de-encapsulated, and the released isocyanate groups can undergo cross-linking reaction with the ring-opening epoxy resin. On the one hand, the introduction of this low-stress modifier can reduce the cross-linking density of the epoxy molding compound and reduce the volume shrinkage during the curing process, thereby reducing the curing stress. On the other hand, the introduction of flexible long-chain alkyl groups into the cross-linking system can improve the flexibility of the system, enhance the deformation resistance of the molding compound, and further reduce the internal stress. Thus, the epoxy molding compound provided by this invention, while ensuring flexural strength, has a significantly reduced coefficient of linear expansion, flexural modulus, and high-temperature flexural modulus, showing excellent heat resistance and low-stress characteristics.
[0029] (2) Cashew phenol-terminated isocyanate has good compatibility with epoxy resin and will not undergo phase separation, which can ensure the stability of the mechanical properties, electrical properties and heat resistance of the molding compound.
[0030] (3) Cashew phenol is a natural renewable resource with wide availability and relatively low price. Using it as a raw material to prepare cashew phenol isocyanate as a low-stress modifier in epoxy molding compound is beneficial to reducing the production cost of epoxy molding compound and is also in line with the green and environmentally friendly development trend. Detailed Implementation
[0031] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.
[0032] The endpoints and any values of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoint values of the various ranges, the endpoint values of the various ranges and individual point values, and individual point values can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.
[0033] Cashew nut shell oil is a natural phenolic compound extracted from cashew nut shell oil. Its molecular structure contains functional groups such as benzene rings, long-chain alkyl groups, and hydroxyl groups, exhibiting good reactivity and flexibility. Through in-depth research, the inventors discovered that end-capped isocyanate compounds prepared from cashew nut shell oil combine the flexible long chains of cashew nut shell oil with the reactivity of isocyanates, showing promise as a novel low-stress modifier for use in epoxy molding compounds.
[0034] Based on this, in a first aspect, the present invention provides an epoxy molding compound containing epoxy resin, phenolic resin, solid filler, accelerator, ion trapping agent, low-stress modifier, coupling agent, release agent, and colorant. Based on a total mass of 100 parts of the epoxy molding compound, the contents of the epoxy resin, phenolic resin, solid filler, accelerator, ion trapping agent, low-stress modifier, coupling agent, release agent, and colorant are 1-30 parts, 1-30 parts, 60-90 parts, 0.01-2 parts, 0.1-1 parts, 0.1-1 parts, 0.1-1 parts, 0.1-1 parts, 0.1-1 parts, and 0.1-1 parts, respectively; wherein the low-stress modifier is cashew phenol-terminated isocyanate.
[0035] In a preferred embodiment, based on a total mass of 100 parts of the epoxy molding compound, the contents of the epoxy resin, the phenolic resin, the solid filler, the accelerator, the ion trapping agent, the low-stress modifier, the coupling agent, the release agent, and the colorant are 8-12 parts, 6-11 parts, 0.15-0.5 parts, 75-85 parts, 0.2-0.6 parts, 0.5-0.7 parts, 0.1-0.2 parts, 0.1-0.3 parts, and 0.3-0.4 parts, respectively.
[0036] The epoxy molding compound provided by this invention has excellent mechanical properties, heat resistance, and electrical properties, and can meet the packaging requirements of high-density, miniaturized electronic devices. Specifically, it achieves the following technical effects: (1) This invention uses cashew phenol-terminated isocyanate as a low-stress modifier. The molecular structure of this low-stress modifier contains flexible long-chain alkyl groups and active isocyanate groups. Under the catalytic action of the accelerator, the cashew phenol-terminated isocyanate can be successfully de-encapsulated, and the released isocyanate groups can undergo cross-linking reaction with the ring-opening epoxy resin. On the one hand, the introduction of this low-stress modifier can reduce the cross-linking density of the epoxy molding compound and reduce the volume shrinkage during the curing process, thereby reducing the curing stress. On the other hand, the introduction of flexible long-chain alkyl groups into the cross-linking system can improve the flexibility of the system, enhance the deformation resistance of the molding compound, and further reduce the internal stress. Thus, the epoxy molding compound provided by this invention, while ensuring flexural strength, has a significantly reduced linear thermal expansion coefficient, flexural modulus, and high-temperature flexural modulus, showing excellent heat resistance and low-stress characteristics.
[0037] (2) Cashew phenol-terminated isocyanate has good compatibility with epoxy resin and will not undergo phase separation, which can ensure the stability of the mechanical properties, electrical properties and heat resistance of the molding compound.
[0038] (3) Cashew phenol is a natural renewable resource with wide availability and relatively low price. Using it as a raw material to prepare cashew phenol isocyanate as a low-stress modifier in epoxy molding compound is beneficial to reducing the production cost of epoxy molding compound and is also in line with the green and environmentally friendly development trend.
[0039] Further research by the inventors revealed that by using cashew phenol-terminated isocyanate (Trixene BI 7774) from Lanxess Asia Pacific Application Development Center as a low-stress modifier in epoxy molding compounds, it can de-encapsulate the terminal isocyanate (releasing free -NCO) under the catalysis of an accelerator, simultaneously generating cashew phenol. At the same time, the accelerator catalyzes the ring-opening of epoxy resin to generate active hydroxyl groups, which undergo cross-linking reactions with free -NCO and cashew phenol, forming a three-dimensional network containing urea-formaldehyde bonds and ether bonds. This reduces the cross-linking density between epoxy resin and phenolic resin, while cashew phenol provides elastic segments to provide toughening and stress-reducing effects to the system.
[0040] In this invention, the epoxy resin can be any epoxy resin material commonly used in the art. Specifically, in some embodiments of this invention, the epoxy resin is selected from at least one of o-cresol epoxy resin, biphenyl-type epoxy resin, aralkyl-type epoxy resin, ester-cyclic epoxy resin, heterocyclic epoxy resin, bisphenol A-type epoxy resin, bisphenol F-type epoxy resin, dicyclopentadiene-type epoxy resin, naphthalene-cyclic epoxy resin, and multifunctional epoxy resin. It can be any one of the above substances, or any combination of two or more of them. It should be noted that when the epoxy resin is a combination of two or more of the above substances, the proportion of each component is not limited and can be combined in any proportion. In a preferred embodiment, the epoxy resin is selected from at least one of biphenyl-type epoxy resin, naphthalene-cyclic epoxy resin, and o-cresol epoxy resin.
[0041] In this invention, the phenolic resin may be any phenolic resin commonly used in the art. Specifically, in some embodiments of this invention, the phenolic resin is selected from at least one of linear phenolic resin, biphenyl-type phenolic resin, naphthylphenol-type phenolic resin, aralkylphenol-type phenolic resin, and multifunctional phenolic resin; it may be any one of the above substances, or any combination of two or more of them. It should be noted that when the phenolic resin is a combination of two or more of the above substances, the proportion of each component is not limited and can be combined in any proportion. Preferably, the phenolic resin is selected from at least one of linear phenolic resin, biphenyl-type phenolic resin, and multifunctional phenolic resin.
[0042] In some embodiments of the present invention, the solid filler is selected from at least one of fused silica powder, crystalline silica powder, alumina, and aluminum nitride, and can be any one of the above substances, or any combination of two or more of them. It should be noted that when the solid filler is a combination of two or more of the above substances, the proportion of each component is not limited and can be combined in any proportion. The main function of the solid filler is to reduce the curing shrinkage rate of the epoxy molding compound and improve its mechanical strength and thermal conductivity. Fused silica powder has a low coefficient of expansion, high insulation properties, and good compatibility with epoxy resin, and is a commonly used filler in epoxy molding compounds; alumina and aluminum nitride have high thermal conductivity and are suitable for encapsulation scenarios requiring high thermal conductivity. In a preferred embodiment, the solid filler is fused silica powder.
[0043] Choosing a filler with a suitable particle size can increase the packing density of the filler in the epoxy resin, further reducing shrinkage and internal stress. Specifically, in some embodiments of the present invention, the particle size of the solid filler is 0.5~100μm. In a preferred embodiment, the median particle size of the solid filler (also known as D50, which refers to the characteristic particle size corresponding to 50% of the cumulative distribution percentage in the particle group, and its physical meaning is that the volume or number of particles larger or smaller than this diameter accounts for 50% of the total volume or total number) is 10~30μm.
[0044] In some embodiments of the present invention, the accelerator is selected from at least one of imidazole accelerators, organophosphorus accelerators, and tertiary amine accelerators. It can be any one of the above substances, or any combination of two or more of them. It should be noted that when the accelerator is a combination of two or three of the above substances, the proportion of each component is not limited and can be combined in any proportion.
[0045] In some embodiments of the present invention, the imidazole accelerator may be selected from at least one of 2-methylimidazole, 2-ethyl-4-methylimidazole, and 1-benzyl-2-methylimidazole, and may be any one of the above substances or any combination of two or more of them. It should be noted that when the imidazole accelerator is a combination of two or three of the above substances, the proportion of each component is not limited and can be combined in any proportion.
[0046] In some embodiments of the present invention, the organophosphorus accelerator is a triphenylphosphine-benzoquinone adduct and / or a tetraphenylphosphine salt, which can be any one of the above substances or any combination of two or more of them. It should be noted that when the imidazole accelerator is a combination of a triphenylphosphine-benzoquinone adduct and a tetraphenylphosphine salt, the ratio of the two is not limited and can be combined in any proportion. Preferably, the accelerator is an organophosphorus accelerator, more preferably a triphenylphosphine-benzoquinone adduct.
[0047] In some embodiments of the present invention, the release agent is selected from at least one of stearic acid, zinc stearate, calcium stearate, oxidized polyethylene wax, and carnauba wax. It can be any one of the above substances, or any combination of two or more of them. It should be noted that when the release agent is a combination of two or more of the above substances, the proportion of each component is not limited and can be combined in any proportion. Preferably, the release agent is oxidized polyethylene wax.
[0048] In some embodiments of the present invention, the ion scavenging agent is a hydrotalcite-based compound. The hydrotalcite-based compound includes hydrotalcite and / or hydrotalcite-like compounds; preferably, the ion scavenging agent is hydrotalcite.
[0049] In some embodiments of the present invention, the coupling agent is selected from γ-ray dihydropyridine (γ-ray dihydropyridine). glycidyl ether trimethoxysilane, γ aminopropyltriethoxysilane, γ mercaptopropyltrimethoxysilane and γ At least one of glycidyl etheroxypropyltrimethoxysilane can be any one of the above substances, or any combination of two or more of them. It should be noted that when the coupling agent is a combination of two or more of the above substances, the proportion of each component is not limited and can be combined in any proportion. Preferably, the coupling agent is γ-hydroxypropyltrimethoxysilane. Glycidyl etheroxypropyltrimethoxysilane.
[0050] In some embodiments of the present invention, the colorant is carbon black.
[0051] Secondly, the present invention provides a method for preparing the above-mentioned epoxy molding compound, the method comprising the following steps: S1. Phenolic resin and low-stress modifier are melt-mixed, and the resulting mixture is made into granules; S2. The granules are mixed with solid fillers, colorants, coupling agents, ion traps, epoxy resins, release agents, and accelerators. The resulting mixture is then melt-mixed, cooled, pulverized, and pre-formed.
[0052] The method provided by this invention uses cashew phenol-terminated isocyanate as a low-stress modifier. The prepared epoxy molding compound has excellent mechanical properties, heat resistance, and electrical properties, which can meet the packaging requirements of high-density, miniaturized semiconductor devices. At the same time, in the preparation process, the low-stress modifier is first premixed with phenolic resin. By optimizing the process of pre-dispersing the low-stress modifier, the low-stress modifier is uniformly dispersed in the epoxy molding compound matrix, thereby further reducing the internal stress after curing.
[0053] In some embodiments of the present invention, the method for preparing epoxy molding compound specifically includes the following steps: First, phenolic resin and low-stress modifier are heated to melt and then melt-mixed. After the materials are evenly mixed, they are cooled, pulverized, and sieved to obtain intermediate granules. Then, the intermediate granules are mixed with solid fillers, colorants, coupling agents, ion scavengers, epoxy resin, release agents, and accelerators. After the materials are fully mixed, the mixture is melt-kneaded. The resulting compound is cooled and pulverized. Finally, it is pre-formed on a patting machine according to the product molding requirements to prepare the epoxy molding compound.
[0054] In the above steps, the conditions for melt mixing of the phenolic resin and the low-stress modifier include: a temperature of 120~150℃, for example, 120℃, 125℃, 130℃, 135℃, 140℃, 145℃, or 150℃. Further, in some embodiments of the present invention, the melt mixing process of the phenolic resin and the low-stress modifier can be carried out in a reactor equipped with a heating mantle, cooling water, and a stirrer. The melt mixing conditions also include: a stirring rate of 150~300 rpm, for example, 150 rpm, 180 rpm, 210 rpm, 240 rpm, 270 rpm, or 300 rpm, and a mixing time of 0.5~2 h, for example, 0.5 h, 1 h, 1.5 h, or 2 h. Additionally, in the step of pulverizing and sieving the melt mixture of the phenolic resin and the low-stress modifier, it is preferable to sieve it through a 30-mesh sieve.
[0055] In the above steps, the process of mixing the intermediate granules with other materials can be carried out in a high-speed mixer. Specifically, the intermediate granules, solid fillers, colorants, coupling agents, ion traps, epoxy resins, release agents, and accelerators are put into a high-speed mixer for mechanical stirring and mixing. The stirring speed of the high-speed mixer is 100~300 rpm, for example, 100 rpm, 150 rpm, 200 rpm, 250 rpm, or 300 rpm. The stirring time of the high-speed mixer is 7~19 min, for example, 7 min, 9 min, 11 min, 13 min, 15 min, 17 min, or 19 min.
[0056] In the above steps, the conditions for melt-blending the mixture include: an outlet temperature of 80~120℃, for example, 80℃, 85℃, 90℃, 95℃, 100℃, 105℃, 110℃, 115℃, or 120℃. Further, in some embodiments of the present invention, the melt-blending process can be carried out in a melt extruder, resulting in better material mixing and higher efficiency. More preferably, it can be carried out in a twin-screw extruder. The melt-blending conditions further include: a screw speed of 200~400 rpm in the melt extruder, for example, 200 rpm, 240 rpm, 280 rpm, 320 rpm, 360 rpm, or 400 rpm.
[0057] Thirdly, the present invention provides an application of the above-mentioned epoxy molding compound in electronic device packaging.
[0058] The epoxy molding compound provided by this invention, while ensuring mechanical properties, reduces the coefficient of linear expansion and flexural modulus, exhibiting excellent mechanical properties, heat resistance, electrical properties, and low stress characteristics. When applied to the packaging of integrated circuits, semiconductors, and other electronic devices, it can meet the packaging requirements of high-density, miniaturized electronic devices, improve packaging efficiency, and enhance the performance stability and lifespan of packaged products. Preferably, the epoxy molding compound provided by this invention is more suitable for the packaging of semiconductor devices.
[0059] The following examples further illustrate the epoxy molding compound, its preparation method, and its application according to the present invention. These examples are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operating procedures; however, the scope of protection of the present invention is not limited to the following examples.
[0060] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods in the art. Unless otherwise specified, the experimental materials used in the following embodiments are commercially available.
[0061] The following examples and comparative examples provide some information about the raw materials used: Cashew phenol-terminated isocyanate, purchased from Lanxess Asia Pacific Application Development Center, brand name Trixene BI 7774.
[0062] The epoxy molding compound formulations in Examples 1-5 are shown in Table 1.
[0063] Table 1
[0064] Example 1 (1) The raw material formula of epoxy molding compound is shown in Table 1.
[0065] (2) Add the multifunctional phenolic resin and cashew phenol-terminated isocyanate to a reactor equipped with a heating jacket, cooling water and a stirrer. Heat to 130°C to melt, then turn on the stirrer for premixing. The stirring speed is 210 rpm and the mixing time is 1 h. After mixing, stir while hot and discharge the material to a tray for cooling. After cooling, crush it with a pulverizer and pass it through a 30-mesh sieve to obtain intermediate granules. (3) Fused silica powder (maximum particle size 75 μm, median particle size 10~30 μm), carbon black, γ Glycidyl etheroxypropyltrimethoxysilane, hydrotalcite, intermediate granules prepared in step (2), biphenyl epoxy resin, o-cresol epoxy resin, oxidized polyethylene wax and triphenylphosphine-benzoquinone adduct were sequentially placed into a high-speed mixer, and stirring was started. The mixture was stirred at 200 rpm for 13 min to obtain the mixture. (4) The mixture prepared in step (3) is fed into a twin-screw extruder and melt-extruded at a discharge outlet temperature of 100°C and a rotation speed of 320 rpm. The extruded product is cooled and crushed in sequence, and then shaped on a briquetting machine as required to obtain epoxy molding compound.
[0066] Example 2 (1) The raw material formula of epoxy molding compound is shown in Table 1.
[0067] (2) Add biphenyl-type phenolic resin and cashew phenol-terminated isocyanate to a reactor equipped with a heating jacket, cooling water and a stirrer. Heat to 130°C to melt, then turn on the stirrer for premixing. The stirring speed is 240 rpm and the mixing time is 0.5 h. After mixing, stir while hot and discharge the material to a tray for cooling. After cooling, crush it with a pulverizer and pass it through a 30-mesh sieve to obtain intermediate granules. (3) Fused silica powder (maximum particle size 75 μm, median particle size 10~30 μm), carbon black, γ Glycidyl etheroxypropyltrimethoxysilane, hydrotalcite, intermediate granules prepared in step (2), naphthalene ring epoxy resin, oxidized polyethylene wax and triphenylphosphine-benzoquinone adduct were sequentially placed into a high-speed mixer, and stirring was started. The mixture was stirred at 150 rpm for 17 min to obtain the mixture. (4) The mixture prepared in step (3) is fed into a twin-screw extruder and melt-extruded at a discharge outlet temperature of 110°C and a rotation speed of 360 rpm. The extruded product is cooled and crushed in sequence, and then shaped on a briquetting machine as required to obtain epoxy molding compound.
[0068] Example 3 (1) The raw material formula of epoxy molding compound is shown in Table 1.
[0069] (2) Linear phenolic resin and cashew phenol-terminated isocyanate were added to a reactor equipped with a heating jacket, cooling water and a stirrer. After heating to 130°C to melt, stirring was started for premixing. The stirring speed was 180 rpm and the mixing time was 1 h. After mixing was completed, the mixture was stirred while hot and discharged to a tray for cooling. After cooling, it was crushed by a pulverizer and passed through a 30-mesh sieve to obtain intermediate granules. (3) Fused silica powder (maximum particle size 75 μm, median particle size 10~30 μm), carbon black, γ Glycidyl etheroxypropyltrimethoxysilane, hydrotalcite, intermediate granules prepared in step (2), naphthalene ring epoxy resin, o-cresol epoxy resin, oxidized polyethylene wax and triphenylphosphine-benzoquinone adduct were sequentially placed into a high-speed mixer, and stirring was started. The mixture was stirred at 250 rpm for 13 min to obtain the mixture. (4) The mixture prepared in step (3) is fed into a twin-screw extruder and melt-extruded at a discharge outlet temperature of 105°C and a rotation speed of 240 rpm. The extruded product is cooled and crushed in sequence, and then shaped on a briquetting machine as required to obtain epoxy molding compound.
[0070] Example 4 (1) The raw material formula of epoxy molding compound is shown in Table 1.
[0071] (2) Add the multifunctional phenolic resin and cashew phenol-terminated isocyanate to a reactor equipped with a heating jacket, cooling water and a stirrer. Heat to 130°C to melt, then turn on the stirrer for premixing. The stirring speed is 210 rpm and the mixing time is 0.5 h. After mixing, stir while hot and discharge the material to a tray for cooling. After cooling, crush it with a pulverizer and pass it through a 30-mesh sieve to obtain intermediate granules. (3) Fused silica powder (maximum particle size 75 μm, median particle size 10~30 μm), carbon black, γ Glycidyl etheroxypropyltrimethoxysilane, hydrotalcite, intermediate granules prepared in step (2), biphenyl epoxy resin, oxidized polyethylene wax and triphenylphosphine-benzoquinone adduct were sequentially placed into a high-speed mixer, and stirring was started. The mixture was stirred at 200 rpm for 9 minutes to obtain the mixture. (4) The mixture prepared in step (3) is fed into a twin-screw extruder and melt-extruded at a discharge outlet temperature of 110°C and a rotation speed of 360 rpm. The extruded product is cooled and crushed in sequence, and then shaped on a briquetting machine as required to obtain epoxy molding compound.
[0072] Example 5 (1) The raw material formula of epoxy molding compound is shown in Table 1.
[0073] (2) Add biphenyl-type phenolic resin and cashew phenol-terminated isocyanate to a reactor equipped with a heating jacket, cooling water and a stirrer. Heat to 130°C to melt, then turn on the stirrer for premixing. The stirring speed is 300 rpm and the mixing time is 0.5 h. After mixing, stir while hot and discharge the material to a tray for cooling. After cooling, crush it with a pulverizer and pass it through a 30-mesh sieve to obtain intermediate granules. (3) Fused silica powder (maximum particle size 75 μm, median particle size 10~30 μm), carbon black, γ Glycidyl etheroxypropyltrimethoxysilane, hydrotalcite, intermediate granules prepared in step (2), biphenyl epoxy resin, oxidized polyethylene wax and triphenylphosphine-benzoquinone adduct were sequentially placed into a high-speed mixer, and stirring was started. The mixture was stirred at 200 rpm for 19 min to obtain the mixture. (4) The mixture prepared in step (3) is fed into a twin-screw extruder and melt-extruded at a discharge outlet temperature of 110°C and a rotation speed of 360 rpm. The extruded product is cooled and crushed in sequence, and then shaped on a briquetting machine as required to obtain epoxy molding compound.
[0074] Comparative Example 1 The epoxy molding compound was prepared according to the method in Example 1, except that cashew phenol-terminated isocyanate was not added to the raw materials as a low-stress modifier.
[0075] Comparative Example 2 The epoxy molding compound was prepared according to the method of Example 2, except that the low-stress modifier in the raw material was replaced by cashew phenol-terminated isocyanate with commercially available carboxyl-terminated liquid nitrile butadiene rubber (CTBN).
[0076] Comparative Example 3 The epoxy molding compound was prepared according to the method in Example 3, except that the low-stress modifier in the raw material was replaced by cashew phenol-terminated isocyanate with commercially available epoxy polyether-modified polysiloxane.
[0077] Comparative Example 4 The epoxy molding compound was prepared according to the method in Example 4, except that the amount of cashew phenol-terminated isocyanate in the raw materials was reduced to 0.34g, and 0.34g of commercially available carboxyl-terminated liquid nitrile butadiene rubber (CTBN) was added.
[0078] Comparative Example 5 The epoxy molding compound was prepared according to the method in Example 5, except that the amount of cashew phenol-terminated isocyanate in the raw materials was reduced to 0.28g, and 0.29g of commercially available epoxy polyether modified polysiloxane was added.
[0079] Comparative Example 6 (1) The raw material formulation of the epoxy molding compound is the same as that in Example 1.
[0080] (2) Multifunctional phenolic resin, cashew phenol-terminated isocyanate, fused silica powder (maximum particle size 75 μm, median particle size 10~30 μm), carbon black, γ Glycidyl etheroxypropyltrimethoxysilane, hydrotalcite, intermediate granules prepared in step (2), biphenyl epoxy resin, o-cresol epoxy resin, oxidized polyethylene wax and triphenylphosphine-benzoquinone adduct were sequentially placed into a high-speed mixer, and stirring was started. The mixture was stirred at 200 rpm for 13 min to obtain the mixture. (3) The mixture prepared in step (2) is fed into a twin-screw extruder and melt-extruded at a discharge outlet temperature of 100°C and a rotation speed of 320 rpm. The extruded product is cooled and crushed in sequence, and then shaped on a briquetting machine as required to obtain epoxy molding compound.
[0081] Test case According to GB / T 40564-2021, the gelation time, spiral flow length, linear thermal expansion coefficient α1 (CET1), linear thermal expansion coefficient α2 (CET2), flexural strength, flexural modulus and flexural modulus at 260℃ of the epoxy molding compound samples prepared in each example and comparative example were tested, and the results are shown in Table 2.
[0082] Table 2
[0083] The following conclusions can be drawn from the results in Table 1: (1) By comparing Examples 1-5 and Comparative Examples 1-5, it can be concluded that the epoxy molding compound prepared by cashew phenol-terminated isocyanate as a low-stress modifier in the embodiments of the present invention has a low linear coefficient of thermal expansion and a significantly reduced flexural modulus while maintaining high flexural strength, showing excellent heat resistance and low stress characteristics.
[0084] (2) By comparing Example 1 and Comparative Example 6, it can be concluded that in the present invention, by first melting and mixing cashew phenol-terminated isocyanate with phenolic resin to pre-disperse cashew phenol-terminated isocyanate, and then mixing it with other components in the raw materials, the epoxy molding compound prepared has a lower linear thermal expansion coefficient and flexural modulus, while the flexural strength does not decrease significantly.
[0085] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.
Claims
1. An epoxy molding compound, characterized in that, The epoxy molding compound contains epoxy resin, phenolic resin, solid filler, accelerator, ion trapping agent, low-stress modifier, coupling agent, release agent, and colorant. Based on a total mass of 100 parts of the epoxy molding compound, the contents of the epoxy resin, phenolic resin, solid filler, accelerator, ion trapping agent, low-stress modifier, coupling agent, release agent, and colorant are 1-30 parts, 1-30 parts, 60-90 parts, 0.01-2 parts, 0.1-1 parts, 0.1-1 parts, 0.1-1 parts, 0.1-1 parts, 0.1-1 parts, and 0.1-1 parts, respectively; wherein the low-stress modifier is cashew phenol-terminated isocyanate.
2. The epoxy molding compound according to claim 1, characterized in that, The epoxy resin is selected from at least one of o-cresol epoxy resin, biphenyl type epoxy resin, aralkyl type epoxy resin, ester ring type epoxy resin, heterocyclic type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, dicyclopentadiene type epoxy resin, naphthalene ring type epoxy resin and multifunctional type epoxy resin. Preferably, the epoxy resin is selected from at least one of biphenyl-type epoxy resin, naphthalene-type epoxy resin, and o-cresol epoxy resin.
3. The epoxy molding compound according to claim 1 or 2, characterized in that, The phenolic resin is selected from at least one of linear phenolic resin, biphenyl-type phenolic resin, naphthalene-type phenolic resin, arylalkylphenol-type phenolic resin, and multifunctional phenolic resin; Preferably, the phenolic resin is selected from at least one of linear phenolic resin, biphenyl-type phenolic resin, and multifunctional phenolic resin.
4. The epoxy molding compound according to any one of claims 1-3, characterized in that, The solid filler is selected from at least one of fused silica powder, crystalline silica powder, alumina and aluminum nitride, preferably fused silica powder.
5. The epoxy molding compound according to any one of claims 1-4, characterized in that, The particle size of the solid filler is 0.5~100μm; Preferably, the median particle size of the solid filler is 10~30μm.
6. The epoxy molding compound according to any one of claims 1-5, characterized in that, The accelerator is selected from at least one of imidazole accelerators, organophosphorus accelerators, and tertiary amine accelerators; Preferably, the imidazole accelerator is selected from at least one of 2-methylimidazole, 2-ethyl-4-methylimidazole, and 1-benzyl-2-methylimidazole; Preferably, the organophosphorus accelerator is a triphenylphosphine-benzoquinone adduct and / or a tetraphenylphosphine salt; Preferably, the accelerator is a triphenylphosphine-benzoquinone adduct.
7. The epoxy molding compound according to any one of claims 1-6, characterized in that, The release agent is selected from at least one of stearic acid, zinc stearate, calcium stearate, oxidized polyethylene wax, and carnauba wax; Preferably, the release agent is oxidized polyethylene wax.
8. The epoxy molding compound according to any one of claims 1-7, characterized in that, The ion-scavenging agent is a hydrotalcite compound, preferably hydrotalcite; and / or, The coupling agent is selected from γ glycidyl ether trimethoxysilane, γ aminopropyltriethoxysilane, γ mercaptopropyltrimethoxysilane and γ At least one of glycidyl etheroxypropyltrimethoxysilane, preferably γ Glycidyl etheroxypropyltrimethoxysilane; and / or, The colorant is carbon black.
9. A method for preparing the epoxy molding compound according to any one of claims 1-8, characterized in that, The method includes the following steps: S1. Phenolic resin and low-stress modifier are melt-mixed, and the resulting mixture is made into granules; S2. The granules are mixed with solid fillers, colorants, coupling agents, ion traps, epoxy resins, release agents and accelerators, and then the resulting mixture is melt-mixed, cooled, pulverized and pre-formed. Preferably, the conditions for melt mixing in step S1 include: a temperature of 120~150℃; Preferably, the conditions for melt mixing in step S2 include a temperature of 80~120℃.
10. The application of the epoxy molding compound according to any one of claims 1-8 in the packaging of electronic devices.