An epoxy resin composition and encapsulating material

Abstract

The application discloses an epoxy resin composition and a packaging material, the epoxy resin composition comprising an epoxy resin, a curing agent and a stress release agent; the structure of the stress release agent is shown in formula (1): wherein R1 and R2 are each independently selected from a hydrogen atom, a C1 to C3 substituted or unsubstituted alkoxy group, a C1 to C3 substituted or unsubstituted alkyl group; R3 is selected from at least one of, n1, n2, n3, n4 and n5 can be independently integers of 5-20 respectively. The epoxy resin provided by the embodiment of the application has a low warpage after curing, and there is no phase separation.

Description

Technical Field

[0001] This application relates to the field of encapsulation materials technology, and in particular to an epoxy resin composition and encapsulation material. Background Technology

[0002] Currently, the integrated circuit industry continues to develop towards higher performance and smaller size, and the performance improvements brought about by Moore's Law are gradually approaching their physical limits. Advanced packaging technology, as a breakthrough solution, has become an important technical route for improving chip integration and performance. Among advanced packaging technologies such as Fan-out, 2.5D CoWoS, 3D packaging, and chiplets, liquid molding compound (LMC) is the core material for achieving wafer reconstruction and multi-chip integration. However, during wafer reconstruction, the material must undergo complex processes such as high-temperature reflow, back grinding, and dicing, which places stringent requirements on LMC warpage control. Warpage not only directly affects product yield and reliability but is also a key factor determining whether high-precision chip interconnection can be achieved. Optimization and improvement of warpage control technology remains a major challenge for the industry.

[0003] In related technologies, stress-relieving agents (such as nitrile rubber) are generally added to epoxy resin to reduce the warpage of the cured material. However, the cured material still has high warpage and phase separation problems. Summary of the Invention

[0004] In view of this, this application provides an epoxy resin composition and an encapsulation material, which aims to improve the problems of high warpage and phase separation in existing encapsulation materials after curing.

[0005] In a first aspect, embodiments of this application provide an epoxy resin composition comprising an epoxy resin, a curing agent, and a stress-relieving agent; the stress-relieving agent has the structure shown in formula (1):

[0006]

[0007] R1 and R2 are each independently selected from hydrogen atoms, C1 to C3 substituted or unsubstituted alkoxy groups, and C1 to C3 substituted or unsubstituted alkyl groups; R3 is selected from... At least one of the following; n1, n2, n3, n4 and n5 can be independent integers from 5 to 20.

[0008] Optionally, R1 and R2 are each independently selected from hydrogen atoms or methoxy groups; and / or

[0009] The raw materials for synthesizing the stress-relieving agent include polyetheramines and allylphenol compounds.

[0010] Optionally, the stress-relieving agent comprises at least one of the structures of formulas (2) to (4):

[0011]

[0012] Optionally, the stress-relieving agent is present in a mass ratio of 0.1% to 3% of the epoxy resin composition; and / or

[0013] The n1 is an integer between 10 and 20; and / or

[0014] The n2 is an integer between 5 and 15; and / or

[0015] The n3, n4, and n5 can be independent integers from 5 to 8.

[0016] Optionally, the stress-relieving agent is used in a mass ratio of 0.1% to 2% of the epoxy resin composition.

[0017] Optionally, the epoxy resin composition further comprises, by weight, an inorganic filler comprising 60% to 93% of the epoxy resin composition; and / or

[0018] The epoxy resin comprises 2% to 10% of the epoxy resin composition; and / or

[0019] The curing agent comprises 3% to 10% of the epoxy resin composition; and / or

[0020] The epoxy resin composition further includes a silane coupling agent, wherein the silane coupling agent accounts for 0.2% to 1% of the epoxy resin composition; and / or

[0021] The epoxy resin composition further includes a curing accelerator, wherein the curing accelerator accounts for 0.1% to 3% of the epoxy resin composition; and / or

[0022] The epoxy resin composition further includes a colorant, which accounts for 0.1% to 1% of the epoxy resin composition.

[0023] Optionally, the epoxy resin includes an epoxy resin that is liquid at room temperature; and / or

[0024] The curing agent includes at least one of aliphatic amines, aromatic amines, phenolic compounds, acid anhydrides, and imidazole compounds; and / or

[0025] The inorganic filler includes at least one of silicon dioxide, alumina, aluminum nitride, silicon carbide, boron nitride, zircon, calcium silicate, calcium carbonate, and barium titanate; and / or

[0026] The inorganic filler has an average particle size of 2 μm to 100 μm; and / or

[0027] The silane coupling agents include γ-(2,3-epoxypropoxy)propyltrimethoxysilane, trimethoxyphenylsilane, 3-aminopropyltriethoxysilane, 3-(isobutenoyloxy)propyltrimethoxysilane, vinyltrimethoxysilane, (3-aminopropyl)triethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-ureapropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, γ-anilinopropyltrimethoxysilane, and γ-anilinopropyltriethoxysilane. At least one of the following: silane, γ-anilinopropylmethyldimethoxysilane, γ-anilinopropylmethyldiethoxysilane, γ-anilinopropylethyldiethoxysilane, γ-anilinopropylethyldimethoxysilane, γ-anilinomethyltrimethoxysilane, γ-anilinomethyltriethoxysilane, γ-anilinomethylmethyldimethoxysilane, γ-anilinomethylmethyldiethoxysilane, γ-anilinomethylethyldiethoxysilane, and γ-anilinomethylethyldimethoxysilane; and / or

[0028] The curing accelerator is an imidazole compound or a tertiary amine salt.

[0029] Optionally, the epoxy resin includes at least one of bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD ​​type epoxy resin, naphthalene ring epoxy resin, aminophenol type epoxy resin, polyalkyl glycol type epoxy resin, and alicyclic epoxy resin.

[0030] Optionally, the bisphenol F type epoxy resin has an epoxy equivalent of 155-165 g / eq; and / or

[0031] The bisphenol A type epoxy resin has an epoxy equivalent of 172-176 g / eq; and / or

[0032] The epoxy equivalent of the naphthalene ring epoxy resin is 136-150 g / eq; and / or

[0033] The alicyclic epoxy resin has an epoxy equivalent of 129-131 g / eq; and / or

[0034] The epoxy resin, by weight, comprises bisphenol F type epoxy resin, bisphenol A type epoxy resin, naphthalene ring epoxy resin, and alicyclic epoxy resin, wherein the ratio of bisphenol F type epoxy resin to bisphenol A type epoxy resin to naphthalene ring epoxy resin to alicyclic epoxy resin is (1.35 to 1.41): (1.5 to 1.6): (1.18 to 1.25): (0.79 to 0.85).

[0035] A second aspect of this application provides an encapsulation material formed by curing the epoxy resin composition.

[0036] Beneficial effects:

[0037] In this application, a stress-relieving agent with a structure of formula (1) is added to the epoxy resin composition. This stress-relieving agent has long, flexible chain segments that can effectively release internal stress, thereby helping to reduce the warpage of the epoxy resin composition. At the same time, the stress-relieving agent has allyl-terminated, phenolic hydroxyl, and imino groups, which can improve its compatibility with epoxy groups and ensure the uniformity of the resin structure. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 Figure a shows the surface morphology of the liquid epoxy composition after curing in Example 2 of this application; Figure b shows the surface morphology of the liquid epoxy composition after curing in Comparative Example 2. Detailed Implementation

[0040] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. Furthermore, it should be understood that the specific embodiments described herein are only for illustration and explanation of this application and are not intended to limit this application.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0042] In this application, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in its actual use or operating state, specifically the drawing directions in the accompanying drawings; while "inner" and "outer" refer to the outline of the device. Furthermore, in the description of this application, the term "comprising" means "including but not limited to". The terms first, second, third, etc., are used merely as illustrative purposes and do not impose numerical requirements or establish a numerical order.

[0043] In this application, "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural.

[0044] In this application, "at least one" means one or more, and "more than one" means two or more. "One or more", "at least one of the following", or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0045] Various embodiments of this application may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a hard limitation on the scope of this application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Furthermore, whenever a numerical range is referred to herein, it means including any referenced number (fraction or integer) within the referred range.

[0046] Currently, the integrated circuit industry continues to develop towards higher performance and smaller size, and the performance improvements brought about by Moore's Law are gradually approaching their physical limits. Advanced packaging technology, as a breakthrough solution, has become an important technical route for improving chip integration and performance. Among advanced packaging technologies such as Fan-out, 2.5D CoWoS, 3D packaging, and chiplets, liquid molding compound (LMC) is the core material for achieving wafer reconstruction and multi-chip integration. However, during wafer reconstruction, the material must undergo complex processes such as high-temperature reflow, back grinding, and dicing, which places stringent requirements on LMC warpage control. Warpage not only directly affects product yield and reliability but is also a key factor determining whether high-precision chip interconnection can be achieved. Optimization and improvement of warpage control technology remains a major challenge for the industry.

[0047] In related technologies, stress-relieving agents (such as nitrile rubber) are generally added to epoxy resin to reduce the warpage of the cured material. However, warpage still exists, and the cured material has phase separation problems.

[0048] In view of this, the present application provides a liquid epoxy resin composition, its preparation method and application, aiming to improve the technical problems of high warpage and phase separation in existing liquid epoxy resin compositions after curing.

[0049] The first aspect of this application provides an epoxy resin composition comprising an epoxy resin, a curing agent, and a stress-relieving agent; the stress-relieving agent has the structure shown in formula (1):

[0050]

[0051] R1 and R2 are each independently selected from hydrogen atoms, C1 to C3 substituted or unsubstituted alkoxy groups, and C1 to C3 substituted or unsubstituted alkyl groups; R3 is selected from... At least one of them; n1, n2, n3, n4 and n5 can be independent integers from 5 to 20, that is, n1, n2, n3, n4 and n5 can be independent integers from 5 to 20.

[0052] It should be noted that the C1 to C3 substituted or unsubstituted alkoxy groups can be substituted or unsubstituted methoxy groups, substituted or unsubstituted ethoxy groups, or substituted or unsubstituted propoxy groups, and are not limited here. Correspondingly, the C1 to C3 substituted or unsubstituted alkyl groups can be substituted or unsubstituted methyl groups, substituted or unsubstituted ethyl groups, or substituted or unsubstituted propyl groups, and are not limited here. It should be noted that if the values ​​of n1, n2, n3, n4, and n5 are too small, for example, less than 5, the flexible chain in the stress-relieving agent molecule is too short, and its toughening and warpage reduction effects are not obvious. If the values ​​of n1, n2, n3, n4, and n5 are too large, for example, greater than 20, the flexible chain in the stress-relieving agent molecule is too long, which can easily lead to a low modulus and unsatisfactory mechanical properties in the cured epoxy resin composition.

[0053] In this application, a stress-relieving agent with the structure of formula (1) is added to the epoxy resin composition. This stress-relieving agent has flexible chain segments of suitable length, which can effectively release internal stress, thereby helping to reduce the warpage of the epoxy resin composition after curing, and at the same time, it has good mechanical properties. At the same time, the stress-relieving agent has allyl-terminated, phenolic hydroxyl, and imino groups, which can improve the compatibility with epoxy groups, ensure the uniformity of the resin structure, and further improve its mechanical properties.

[0054] In some embodiments of this application, the stress-relieving agent comprises at least one of the structures of formulas (2) to (4):

[0055]

[0056]

[0057] In some embodiments of this application, the stress-relieving agent has the structure shown in formula (2). Further, n2 is an integer from 5 to 15, that is, n2 is an integer from 5 to 15. For example, n2 is 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15.

[0058] For example, the stress-relieving agent with the structure shown in formula (2) can be prepared by the following synthetic route: 20.00 g of polyetheramine with an average molecular weight of 400 (0.05 mol), 16.42 g of 4-allyl-2-methoxyphenol (0.1 mol) and 3.00 g of formaldehyde (0.1 mol) are mixed and stirred at 80 °C for 4 h until the reaction solution is clear. The resulting liquid is then dried under vacuum at 80 °C for 6 h to obtain the compound with the structure shown in formula (2).

[0059] In some embodiments of this application, the stress-relieving agent has the structure shown in formula (3). Further, n1 is an integer from 10 to 20, that is, n1 is an integer from 10 to 20. For example, n1 is 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20.

[0060] For example, the stress-relieving agent with the structure shown in formula (3) can be prepared by the following synthetic route: 20.00 g (0.01 mol) of polyethylene glycol diamine with an average molecular weight of 600, 13.42 g (0.1 mol) of 2-allyl-phenol, and 3.00 g (0.1 mol) of formaldehyde are added to a reactor in stoichiometric ratio, and the mixture is heated to 60 °C and stirred. After the reaction solution is clarified (approximately 4 h), it is dried under vacuum at 80 °C for 6 h to obtain the compound with the structure shown in formula (3).

[0061] In some embodiments of this application, the stress-relieving agent has the structure shown in formula (4). Further, n3, n4, and n5 can be independently integers from 5 to 8.

[0062] For example, the stress-relieving agent with the structure shown in formula (4) can be prepared by the following synthetic route: 20.00 g of polyetheramine (0.045 mol), 13.42 g of 4-allyl-phenol (0.1 mol), and 3.00 g of formaldehyde (0.1 mol) with an average molecular weight of 440 are mixed and stirred vigorously at 60 °C for 4 h until the reaction solution is clear. The resulting liquid is then dried under vacuum at 80 °C for 6 h to obtain the compound of formula (4).

[0063] It should be noted that the structural stress-relieving agents shown in formulas (2), (3), and (4) of this application are also commercially available and are not limited here. The stress-relieving agent shown in formula (2) can be understood to include at least one of a plurality of compounds corresponding to an integer n2 of 5 to 15. Similarly, the stress-relieving agent shown in formula (3) can be understood to include at least one of a plurality of compounds corresponding to an integer n1 of 10 to 20. The stress-relieving agent shown in formula (4) can be understood to include at least one of a plurality of compounds corresponding to an integer n3, n4, and n5 that can independently be integers from 5 to 8.

[0064] In some embodiments of this application, the mass ratio of the stress-relieving agent to the epoxy resin composition is 0.5% to 3% by weight. Exemplarily, the mass ratio of the stress-relieving agent to the epoxy resin composition is 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2%, 2.1%, 2.2%, 2.3%, 2.4%, 2.5%, 2.6%, 2.7%, 2.8%, 2.9%, 3%, and values ​​between any two of the above.

[0065] In some embodiments of this application, the mass ratio of the epoxy resin to the epoxy resin composition is 2% to 10% by weight. Exemplarily, the mass ratio of the epoxy resin to the epoxy resin composition is 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, and values ​​between any two of the above.

[0066] In some embodiments of this application, the epoxy resin includes an epoxy resin that is liquid at room temperature. Exemplarily, the epoxy resin includes at least one of bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD ​​type epoxy resin, dihydroxynaphthalene type epoxy resin, aminophenol type epoxy resin, and polyalkyl glycol type epoxy resin. Preferably, the epoxy resin includes one or a combination of several of bisphenol A type epoxy resin, bisphenol F type epoxy resin, naphthalene type epoxy resin, and alicyclic epoxy resin.

[0067] In some embodiments of this application, the curing agent includes at least one of aliphatic amines, aromatic amines, phenolic compounds, acid anhydrides, and imidazole compounds.

[0068] For example, the fatty amines include diethylenetriamine, triethylenetetramine, tetraethylenepentamine, polyetheramine, and isophorone diamine.

[0069] For example, the aromatic amines include m-phenylenediamine, diaminodiphenylmethane, and diaminodiphenyl sulfone.

[0070] Exemplarily, the acid anhydrides include at least one of phthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, tetrahydrophthalic anhydride, maleic anhydride, and succinic anhydride. Exemplarily, the curing agent is one or a combination of m-phenylenediamine and diethyltetramethylimidazole.

[0071] For example, the imidazole compounds include dimethylimidazole and diethyltetramethylimidazole.

[0072] Preferably, the curing agent is one or a combination of m-phenylenediamine, diethyltetramethylimidazole.

[0073] In some embodiments of this application, the content of the curing agent to the epoxy resin composition is 3% to 10% by mass. Exemplarily, the mass ratio of the epoxy resin to the epoxy resin composition is 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, and any two of the above values.

[0074] In some embodiments of this application, the epoxy resin composition further includes an inorganic filler, wherein the mass ratio of the inorganic filler to the epoxy resin composition is 60% to 93% by weight. Exemplarily, the mass ratio of the epoxy resin to the epoxy resin composition is 60%, 62%, 65%, 68%, 70%, 72%, 75%, 78%, 80%, 82%, 84%, 86%, 88%, 90%, 91%, 92%, 93%, or any value between any two of the above.

[0075] It should be noted that if the content of inorganic filler in the epoxy resin composition is too low, for example, below 60%, the viscosity of the liquid epoxy resin composition is too low, and its compatibility with existing processes is not ideal; if the content of inorganic filler in the epoxy resin composition is too high, for example, above 93%, the fluidity of the liquid epoxy resin composition deteriorates, which can easily lead to defects such as incomplete filling during the encapsulation process.

[0076] In some embodiments of this application, the inorganic filler includes at least one selected from silicon dioxide, alumina, aluminum nitride, silicon carbide, boron nitride, zircon, calcium silicate, calcium carbonate, and barium titanate. Exemplarily, the inorganic filler is spherical.

[0077] Further, the average particle size of the inorganic filler is 2μm to 100μm, that is, the average particle size of the inorganic filler is 2μm to 100μm. For example, the average particle size of the inorganic filler is 2μm, 5μm, 10μm, 15μm, 20μm, 25μm, 30μm, 35μm, 40μm, 45μm, 50μm, 55μm, 60μm, 65μm, 70μm, 75μm, 80μm, 85μm, 90μm, 95μm, 100μm, and any value between any two of the above. Further, the average particle size of the inorganic filler is 25μm to 75μm.

[0078] In some embodiments of this application, the average particle size of the inorganic filler is 2 μm to 50 μm. Further, the average particle size of the inorganic filler is 10 μm to 20 μm.

[0079] In some embodiments of this application, the epoxy resin composition further includes a silane coupling agent, wherein the mass ratio of the silane coupling agent to the epoxy resin composition is 0.2% to 1% by weight. Exemplarily, the mass ratio of the silane coupling agent to the epoxy resin composition is 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, or any value between any two of the above.

[0080] In some embodiments of this application, the silane coupling agent includes γ-(2,3-epoxypropoxy)propyltrimethoxysilane, trimethyloxyphenylsilane, 3-aminopropyltriethoxysilane, 3-(isobutenoyloxy)propyltrimethoxysilane, vinyltrimethoxysilane, (3-aminopropyl)triethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-ureapropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, γ-anilinepropyltrimethoxysilane, γ-aniline At least one of γ-propyltriethoxysilane, γ-anilinopropylmethyldimethoxysilane, γ-anilinopropylmethyldiethoxysilane, γ-anilinopropylethyldiethoxysilane, γ-anilinopropylethyldimethoxysilane, γ-anilinomethyltrimethoxysilane, γ-anilinomethyltriethoxysilane, γ-anilinomethylmethyldimethoxysilane, γ-anilinomethylmethyldiethoxysilane, γ-anilinomethylethyldiethoxysilane, and γ-anilinomethylethyldimethoxysilane.

[0081] In some embodiments of this application, the epoxy resin composition further includes a curing accelerator, wherein the mass ratio of the curing accelerator to the epoxy resin composition is 0.1% to 3% by weight. Exemplarily, the mass ratio of the curing accelerator to the epoxy resin composition is 0.1%, 0.2%, 0.4%, 0.5%, 0.7%, 0.8%, 1%, 1.2%, 1.4%, 1.6%, 1.8%, 2%, 2.2%, 2.4%, 2.6%, 2.8%, 3%, or any value between any two of the above. Preferably, the mass ratio of the curing accelerator to the epoxy resin composition is 0.2% to 2%.

[0082] For example, the curing accelerator is an imidazole compound or a tertiary amine salt. For instance, the curing accelerator includes at least one of 2-methylimidazole, 2-phenylimidazole, and 2-phenyl-4-methylimidazole.

[0083] In some embodiments of this application, the epoxy resin composition further includes a colorant, wherein the mass ratio of the colorant to the epoxy resin composition is 0.1% to 1% by weight. Exemplarily, the mass ratio of the curing accelerator to the epoxy resin composition is 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, or any value between any two of the above. Further, the mass ratio of the colorant to the epoxy resin composition is 0.1% to 0.6%. It should be noted that the specific type of colorant is not a major improvement of this application and is not limited thereto.

[0084] In some embodiments of this application, the epoxy resin composition, by weight, comprises epoxy resin, curing agent, inorganic filler, curing accelerator, silane coupling agent, stress relief agent, and colorant, wherein the epoxy resin : curing agent : inorganic filler : curing accelerator : silane coupling agent : stress relief agent : colorant is (2-10): (3-10): (60-93): (0.3-3): (0.5-1): (0.1-1).

[0085] In some embodiments of this application, the epoxy resin composition comprises, by weight, epoxy resin, curing agent, inorganic filler, curing accelerator, silane coupling agent, stress relief agent and colorant.

[0086] In some embodiments of this application, the epoxy resin composition comprises, by weight, 0.5-25 parts of epoxy resin (i.e., 0.5 to 25 parts), 1-20 parts of curing agent, 60-92 parts of inorganic filler, 0.05-2 parts of curing accelerator, 0.05-5 parts of silane coupling agent, 0.005-2 parts of stress relief agent, and 0.1 to 0.6 parts of colorant.

[0087] This application also provides a method for preparing an epoxy resin composition, comprising the following steps: adding epoxy resin, curing agent, inorganic filler, curing accelerator, silane coupling agent, stress relief agent and colorant into a reaction vessel according to the specified ratio, and dispersing and mixing them at 40-60°C to obtain the liquid epoxy resin composition.

[0088] The epoxy resin composition in this application will be further described below with reference to specific experimental tests.

[0089] Each example (Example 1 in Table 1 is abbreviated as "S1", Example 2 as "S2", and so on) and the comparative example (Comparative Example 1 in Table 1 is abbreviated as "D1", and so on) were prepared according to the raw material composition and mass ratio in Table 1 and Table 2, and the samples for mechanical property testing were obtained after curing using the same curing process.

[0090] Table 1

[0091]

[0092]

[0093] Note: In Table 1, " / " indicates that it was not included.

[0094] Table 2 Experimental Materials

[0095] A1 Bisphenol F type epoxy resin, epoxy equivalent 155-165g / eq. A2 Bisphenol A type epoxy resin, epoxy equivalent 172-176 g / eq. A3 Naphthalene ring epoxy resin, epoxy equivalent 136-150 g / eq. A4 Alicyclic epoxy resin, epoxy equivalent 130 g / eq. B Diethylenetriamine C <![CDATA[Fused spherical SiO2]]> D 2-Phenylacetyl-4-methylimidazolium E1 γ-Anilinemethylmethyldimethoxysilane E2 γ-(2,3-epoxypropoxy)propyltrimethoxysilane F1 Compounds with the structure shown in formula (2) F2 Compounds with the structure shown in formula (3) F3 Compounds with the structure shown in formula (4) F4 Nitrile rubber G carbon black

[0096] Experimental Test

[0097] Viscosity measurement: The viscosity was measured using an E-type viscometer at a rate of 25 revolutions per minute. The unit of viscosity is Pa·s.

[0098] Warpage Measurement: On a 750 μm thick, 300 mm diameter wafer, a sealing resin composition was compressed for 5 minutes at 5 MPa and 125 °C using a TOWA compression molding machine to obtain a 500 μm thick encapsulation material. The prepared compression-molded sample was cured at 150 °C for 2 hours to obtain a sample for warpage testing. The warpage of the sample was determined using the TMD (Topological Deformation Measurement) method: The encapsulated wafer was placed on a TMD device for high-precision three-dimensional topological scanning to obtain surface morphology data; the warpage deformation was calculated by analyzing the height deviation and deformation of the sample surface.

[0099] Mechanical property determination: Place a standard-sized specimen on two support points, apply a vertical load at a constant speed at the center of the specimen, record the force and deflection data during the loading process, and calculate the bending strength and bending modulus of the material using formulas.

[0100] Viscosity, warpage, and mechanical properties were tested for each experimental example, and the test results are shown in Table 3.

[0101] Table 3

[0102]

[0103]

[0104] The difference between Examples 1 to 12 and Comparative Example 3 lies in whether or not a stress-relieving agent is added. The test results show that the warpage deformation of Examples 1 to 12 is far lower than that of Comparative Example 3, and the flexural strength is also improved to some extent. This indicates that adding a stress-relieving agent of formula (1) in the embodiments of this application is beneficial in reducing the warpage deformation of epoxy resin and improving its flexural strength. It is worth mentioning that in related technologies, nitrile rubber is generally added to epoxy resin compositions to reduce its warpage deformation. The stress-relieving agent of formula (1) in this application has a lower warpage deformation compared to nitrile rubber, demonstrating a surprising effect.

[0105] Furthermore, it is worth mentioning that the stress-relieving agent with the structure of formula (1) added in the embodiments of this application also solves the problem of phase separation when adding nitrile rubber to epoxy resin compositions in related technologies. Figure 1 Figure b shows the surface morphology of the cured liquid epoxy composition in Comparative Example 2. Obvious phase separation is observed, indicating significant precipitation of the stress-relieving agent. Under otherwise unchanged conditions, the phase separation phenomenon disappeared when nitrile rubber was removed in Comparative Example 3. This shows that although adding nitrile rubber to the epoxy resin composition can significantly reduce its warpage, it still results in phase separation after curing. Figure 1 Figure a shows the surface morphology of the liquid epoxy composition after curing in Example 2. The observation results show that the surface of the cured product is uniform and dense, and there is no phase separation phenomenon caused by the precipitation of stress release agent.

[0106] The test results from Examples 1 to 10 show that as the content of stress-relieving agent in the epoxy resin composition increases, its warpage gradually decreases, but its mechanical properties gradually decrease while its viscosity gradually increases. When the content of stress-relieving agent is less than 2 parts, its flexural strength is greater than 70 MPa, and its viscosity at room temperature is less than 800 Pa·s. This makes it suitable for existing liquid molding compound molding processes and exhibits high mechanical properties and low warpage performance.

[0107] A comparison of Examples 1 to 6 shows that the addition of the stress-relieving agent shown in Formula (3) to the epoxy resin composition results in a lower warpage compared to the stress-relieving agents shown in Formulas (2) and (4). This is likely because the stress-relieving agent in Formula (3) has better chain segment flexibility, which is more conducive to reducing the warpage of the epoxy resin composition containing it.

[0108] The difference between Example 1 and Example 2 lies in the different silane coupling agents used. The test results show that the silane coupling agent used in Example 2 can make the material have higher flexural strength and full modulus, and higher viscosity, indicating that its toughness is relatively high and warpage is reduced.

[0109] The technical solutions provided by the embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. An epoxy resin composition, characterized by comprising: The composition includes epoxy resin, curing agent, and stress-relieving agent; the stress-relieving agent includes at least one of the structures of formulas (2) to (4); the mass ratio of the stress-relieving agent to the epoxy resin composition is 0.1% to 3%. Formula (2); Formula (3); Formula (4); n1, n2, n3, n4, and n5 can be independent integers from 5 to 20; The compound with the structure shown in formula (2) was prepared by the following synthetic route: polyetheramine with an average molecular weight of 400, 4-allyl-2-methoxyphenol and formaldehyde were mixed in a molar ratio of 0.05:0.1:0.1, and the reaction solution was stirred at 80°C until it became clear. The resulting liquid was dried under vacuum at 80°C for 6 h to obtain the compound with the structure shown in formula (2). The compound with the structure shown in formula (3) was prepared by the following synthetic route: polyethylene glycol diamine with an average molecular weight of 600, 2-allyl-phenol and formaldehyde were added to the reactor in a molar ratio of 0.01:0.1:0.1 according to the stoichiometric ratio, heated to 60°C and stirred for reaction. After the reaction solution was clarified, it was dried under vacuum at 80°C for 6 hours to obtain the compound with the structure shown in formula (3). The compound with the structure shown in formula (4) was prepared by the following synthetic route: polyetheramine with an average molecular weight of 440, 4-allyl-phenol and formaldehyde were mixed in a molar ratio of 0.045:0.1:0.1 and stirred vigorously at 60°C until the reaction solution was clear. The resulting liquid was dried under vacuum at 80°C for 6 h to obtain the compound of formula (4).

2. The epoxy resin composition according to claim 1, wherein The stress-relieving agent is present in a mass ratio of 0.1% to 2% of the epoxy resin composition.

3. The epoxy resin composition according to claim 1, characterized in that, The epoxy resin composition further comprises, by weight, inorganic fillers, wherein the inorganic fillers constitute 60% to 93% of the epoxy resin composition; and / or The epoxy resin accounts for 2% to 10% of the epoxy resin composition; and / or The curing agent comprises 3% to 10% of the epoxy resin composition; and / or The epoxy resin composition further includes a silane coupling agent, wherein the silane coupling agent accounts for 0.2% to 1% of the epoxy resin composition; and / or The epoxy resin composition further includes a curing accelerator, wherein the curing accelerator accounts for 0.1% to 3% of the epoxy resin composition; and / or The epoxy resin composition further includes a colorant, which accounts for 0.1% to 1% of the epoxy resin composition.

4. The epoxy resin composition according to claim 3, characterized in that, The epoxy resin includes epoxy resin that is liquid at room temperature; and / or The curing agent includes at least one of aliphatic amines, aromatic amines, phenolic compounds, acid anhydrides, and imidazole compounds; and / or The inorganic filler includes at least one of silicon dioxide, alumina, aluminum nitride, silicon carbide, boron nitride, zircon, calcium silicate, calcium carbonate, and barium titanate; and / or The inorganic filler has an average particle size of 2 μm to 100 μm; and / or The silane coupling agent includes γ-(2,3-epoxypropoxy)propyltrimethoxysilane, trimethoxyphenylsilane, 3-aminopropyltriethoxysilane, 3-(isobutenoyloxy)propyltrimethoxysilane, vinyltrimethoxysilane, γ-ureapropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, γ-anilinopropyltrimethoxysilane, γ-anilinopropyltriethoxysilane, and γ-anilinopropylmethyldimethylsilane. At least one of the following: γ-anilinepropylmethyldiethoxysilane, γ-anilinepropylethyldiethoxysilane, γ-anilinepropylethyldimethoxysilane, γ-anilinemethyltrimethoxysilane, γ-anilinemethyltriethoxysilane, γ-anilinemethylmethyldimethoxysilane, γ-anilinemethylmethyldiethoxysilane, γ-anilinemethylethyldiethoxysilane, and γ-anilinemethylethyldimethoxysilane; and / or The curing accelerator is an imidazole compound or a tertiary amine salt.

5. The epoxy resin composition according to claim 1, characterized in that, The epoxy resin includes at least one of bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD ​​type epoxy resin, naphthalene ring epoxy resin, aminophenol type epoxy resin, polyalkyl glycol type epoxy resin, and alicyclic epoxy resin.

6. The epoxy resin composition according to claim 5, characterized in that, The bisphenol F type epoxy resin has an epoxy equivalent of 155-165 g / eq; and / or The bisphenol A type epoxy resin has an epoxy equivalent of 172-176 g / eq; and / or The epoxy equivalent of the naphthalene ring epoxy resin is 136-150 g / eq; and / or The alicyclic epoxy resin has an epoxy equivalent of 129-131 g / eq; and / or The epoxy resin includes bisphenol F type epoxy resin, bisphenol A type epoxy resin, naphthalene ring epoxy resin and alicyclic epoxy resin, wherein the mass ratio of bisphenol F type epoxy resin: bisphenol A type epoxy resin: naphthalene ring epoxy resin: alicyclic epoxy resin is (1.35 to 1.41): (1.5 to 1.6): (1.18 to 1.25): (0.79 to 0.85).

7. An encapsulation material, characterized in that, The encapsulation material is formed by curing the epoxy resin composition according to any one of claims 1 to 6.

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