A high-temperature resistant bottom-filled epoxy adhesive, its preparation method and application

Abstract

This invention belongs to the field of adhesives and sealants, specifically relating to a high-temperature resistant underfill epoxy adhesive, its preparation method, and its application. The high-temperature resistant underfill epoxy adhesive contains a phenyl trifunctional epoxy monomer, an epoxy resin, a toughening resin, a curing agent, a curing accelerator, a coupling agent, and inorganic fillers, as well as optional additives; the epoxy resin is an epoxy resin that includes at least bisphenol F diglycidyl ether. The key to this invention is combining a phenyl trifunctional epoxy monomer having the structure shown in formula (1) with an epoxy resin that includes at least bisphenol F diglycidyl ether to obtain an underfill epoxy adhesive. This combination achieves low viscosity and good flowability while improving the heat resistance of the cured underfill epoxy adhesive.

Description

Technical Field

[0001] This invention belongs to the field of adhesives and sealants, specifically relating to a high-temperature resistant bottom-filled epoxy adhesive, its preparation method, and its application. Background Technology

[0002] Flip-chip bonding technology uses the bumps of a flip chip as the connection medium, employing reflow soldering and thermoforming to interconnect the chip with the printed circuit board (PCB). It is one of the mainstream high-speed, high-density packaging technologies. During flip-chip bonding, due to the mismatch in thermal expansion coefficients between the chip and the substrate, significant thermal stress occurs with temperature changes. Therefore, underfill adhesive is often used between the chip and the substrate for reinforcement. Underfill methods are generally divided into two types: flow underfill and non-flow underfill. Flow underfill involves injecting underfill adhesive onto the chip edge after the bumps have reflowed, using capillary action to fill the space between the chip and the substrate. Non-flow underfill involves first applying underfill adhesive to an appropriate location on the substrate surface before mounting the flip chip. Because flow underfill requires less sophisticated equipment and is simpler to operate, it is widely used in flip-chip bonding and plays a crucial role in the electronic chip manufacturing process.

[0003] The increasing integration and performance of electronic chips have placed higher demands on the performance of underfill adhesives. Based on process and performance requirements, underfill adhesives need to possess basic characteristics such as ease of handling, rapid flow, rapid curing, long service life, high bond strength, and low modulus, while also meeting requirements for filler properties, compatibility, and reworkability. Epoxy resins typically have high viscosity; achieving low viscosity is key to ensuring the ease of handling of epoxy resin underfill adhesives. Furthermore, the coefficient of linear expansion (CTE) of the underfill adhesive needs to match that of the substrate. Generally, a higher glass transition temperature (Tg) results in a longer thermal cycling fatigue life, and since electronic components generate heat during operation, the cured material also needs good heat resistance. However, existing underfill adhesives still require further improvement in terms of low viscosity and high performance characteristics such as heat resistance.

[0004] In summary, how to prepare an underfill epoxy adhesive with both low viscosity and high heat resistance using a suitable epoxy resin combination has become an urgent problem to be solved. Summary of the Invention

[0005] One of the objectives of this invention is to address the shortcomings of existing underfill epoxy adhesives, which have high viscosity and poor heat resistance, by providing an underfill epoxy adhesive that simultaneously possesses low viscosity and high heat resistance.

[0006] The second objective of this invention is to provide a method for preparing the above-mentioned high-temperature resistant bottom-filled epoxy adhesive.

[0007] The third objective of this invention is to provide the application of the above-mentioned high-temperature resistant bottom-filling epoxy adhesive in the chip and PCB substrate packaging process.

[0008] Specifically, the high-temperature resistant bottom-filled epoxy adhesive provided by the present invention contains a phenyl trifunctional epoxy monomer, an epoxy resin, a toughening resin, a curing agent, a curing accelerator, a coupling agent, an inorganic filler, and optional additives.

[0009] The phenyl trifunctional epoxy monomer has the structure shown in formula (1):

[0010]

[0011] In formula (1), R1, R2 and R3 are each independently a C1 to C5 alkylene group;

[0012] The epoxy resin is an epoxy resin that includes at least bisphenol F diglycidyl ether.

[0013] In a preferred embodiment, the content of the phenyl trifunctional epoxy monomer is 10-20 parts by weight, the content of the epoxy resin is 10-30 parts by weight, the content of the toughening resin is 5-20 parts by weight, the content of the curing agent is 14-30 parts by weight, the content of the curing accelerator is 0.05-3 parts by weight, the content of the coupling agent is 0.1-3 parts by weight, the content of the inorganic filler is 50-80 parts by weight, and the content of the additives is 0.1-10 parts by weight.

[0014] In a preferred embodiment, the phenyl trifunctional epoxy monomer is prepared by the following method:

[0015] S1. The alkenyl-alkoxyphenol having the structure shown in formula (2) is hydrolyzed in the presence of a catalyst and an organosilane compound and then purified to obtain the first intermediate product having the structure shown in formula (3).

[0016] S2. The first intermediate product is purified by condensation reaction with an alkenyl halide compound having the structure shown in formula (4) in the presence of an alkaline compound and a phase transfer catalyst to obtain a second intermediate product having the structure shown in formula (5).

[0017] S3. The second intermediate product is oxidized in the presence of an oxidant and then purified to obtain a phenyl trifunctional epoxy monomer.

[0018]

[0019] In formula (2), R1 and R4 are each independently a C1 to C5 alkylene group;

[0020] In formula (3), R1 is a C1 to C5 alkylene group;

[0021] In formula (4), R2 is a C1 to C5 alkylene group, and X is a halogen;

[0022] In formula (5), R1 and R2 are each independently selected from C1 to C5 alkylene groups.

[0023] In a preferred embodiment, the ratio of the alkenyl-alkoxyphenol, catalyst, organosilanes, basic compounds, phase transfer catalyst, alkenyl halogenated compounds, and oxidant is 1 mol:(0.001–0.006) mol:(200–3000) mL:(1–3) mol:(0.05–0.15) mol:(1.5–4.5) mol:(2.5–3.5) mol.

[0024] In a preferred embodiment, the catalyst is selected from at least one of tris(pentafluorophenyl)borane, triphenylmethyltetra(pentafluorophenyl)borate, dimethylbis(octadecylbenzene-1,4-diaminotetra(pentafluorophenyl)borate, N,N-dimethylphenylammoniumtetra(pentafluorophenyl)borate, N,N-bis(octadecylbenzene)moniumtetra(pentafluorophenyl)borate, N-methyldiphenylammoniumtetra(pentafluorophenyl)borate, and potassium tetra(pentafluorophenyl)borate.

[0025] In a preferred embodiment, the organosilane compound is selected from at least one of trimethylsilane, triethylsilane, triisopropylsilane, tributylsilane, and polymethylsiloxane.

[0026] In a preferred embodiment, the alkaline compound is selected from at least one of potassium hydroxide, sodium hydroxide, magnesium hydroxide, calcium hydroxide, barium hydroxide, sodium carbonate, and potassium carbonate.

[0027] In a preferred embodiment, the phase transfer catalyst is selected from at least one of cyclic crown ethers, polyethers, and ammonium compounds.

[0028] In a preferred embodiment, the alkenyl halogenated compound is selected from at least one of allyl bromide, allyl chloride, allyl iodide, bromobutene, bromopentene, bromohexene, bromoheptene, and chlorobutene.

[0029] In a preferred embodiment, the oxidant is selected from at least one of m-chloroperoxybenzoic acid, hydrogen peroxide, peroxybenzoic acid, peracetic acid, and peroxyformic acid.

[0030] In a preferred embodiment, the mass ratio of the phenyl trifunctional epoxy monomer to the epoxy resin is 1:(0.5-2.0).

[0031] In a preferred embodiment, the epoxy resin is a mixture of bisphenol F diglycidyl ether and an alicyclic epoxy resin.

[0032] In a preferred embodiment, the mass ratio of bisphenol F diglycidyl ether to alicyclic epoxy resin in the epoxy resin is 1:(0.1-0.7).

[0033] In a preferred embodiment, the equivalent ratio of epoxy groups in the epoxy resin to active functional groups in the curing agent is 1:(0.4-1.3).

[0034] In a preferred embodiment, the toughening resin is selected from at least one of liquid nitrile rubber, liquid polybutadiene, liquid polysulfide rubber, chloroprene rubber, cashew shell liquid modified phenolic resin, polyester resin, epoxy resin active toughening agent, SBS thermoplastic elastomer, polyvinyl alcohol methyl acetal, polyethersulfone, polyimide, polyetherimide, polyetheretherketone, polyether diol, and polyether triol.

[0035] In a preferred embodiment, the curing agent is selected from at least one of amine curing agents, acid anhydride curing agents, phenolic curing agents, imidazole curing agents, and latent curing agents.

[0036] In a preferred embodiment, the curing accelerator is selected from at least one of imidazole compounds, amine compounds, and phosphorus compounds.

[0037] In a preferred embodiment, the coupling agent is selected from at least one of γ-methacryloxypropyltrimethoxysilane, vinyltri(β-methoxyethoxy)silane, vinyltrimethoxysilane, vinyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, anilinemethyltriethoxysilane, γ-(2,3-epoxypropoxy)propyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and γ-ureapropyltriethoxysilane.

[0038] In a preferred embodiment, the inorganic filler is selected from at least one of carbon black, silica, alumina, talc, calcium carbonate, glass microspheres, metal powder, and polytetrafluoroethylene filler.

[0039] In a preferred embodiment, the additive is selected from at least one of stabilizers, polymerization inhibitors, antioxidants, flame retardants, diluents, adhesion promoters, dyes, pigments, defoamers, leveling agents, homogenizers, and ion trapping agents.

[0040] The preparation method of the high-temperature resistant bottom-filled epoxy adhesive provided by the present invention includes mixing phenyl trifunctional epoxy monomer, epoxy resin, toughening resin, curing agent, curing accelerator, coupling agent, inorganic filler and optional additives evenly to obtain the high-temperature resistant bottom-filled epoxy adhesive.

[0041] Furthermore, the present invention also provides the application of the high-temperature resistant bottom-filling epoxy adhesive in the chip and PCB substrate packaging process.

[0042] The key to this invention is to combine a phenyl trifunctional epoxy monomer having the structure shown in formula (1) with an epoxy resin that includes at least bisphenol F diglycidyl ether to obtain an underfilled epoxy adhesive. This can improve the heat resistance of the underfilled epoxy adhesive after curing while achieving low viscosity and good flowability. Attached Figure Description

[0043] Figure 1 The Fourier transform infrared spectrum is shown for the 1,2,4-phenyl trifunctional epoxy monomer obtained in Example 1. Detailed Implementation

[0044] The high-temperature resistant bottom-filled epoxy adhesive provided by the present invention contains phenyl trifunctional epoxy monomer, epoxy resin, toughening resin, curing agent, curing accelerator, coupling agent, inorganic filler, and optional additives. The phenyl trifunctional epoxy monomer comprises 10-20 parts by weight, such as 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 parts by weight or any value between them; the epoxy resin comprises 10-30 parts by weight, such as 10, 12, 15, 18, 20, 22, 25, 28, 30 parts by weight or any value between them; the toughening resin comprises 5-20 parts by weight, such as 5, 8, 10, 12, 15, 18, 20 parts by weight or any value between them; the curing agent comprises 14-30 parts by weight, such as 14, 18, 20, 25, 30, 35, 40, 45, 50, 55, 60 or any value between them; and the curing accelerator comprises 0 parts by weight. The content of the coupling agent is 0.1 to 3 parts by weight, such as 0.1, 0.2, 0.5, 0.8, 1, 1.2, 1.5, 1.8, 2, 2.2, 2.5, 2.8, 3 parts by weight or any value between them; the content of the inorganic filler is 50 to 80 parts by weight, such as 50, 52, 55, 58, 60, 62, 65, 68, 70, 72, 75, 78, 80 or any value between them; the content of the auxiliary agent is 0.1 to 10 parts by weight, such as 0.1, 0.2, 0.5, 0.8, 1, 2, 5, 8, 10 or any value between them.

[0045] In this invention, the phenyl trifunctional epoxy monomer has the structure shown in formula (1):

[0046]

[0047] In formula (1), R1, R2, and R3 are each independently selected from C1 to C5 alkylene groups. Specific examples of the C1 to C5 alkylene groups include, but are not limited to, at least one of methylene, ethylene, propylene, butylene, and pentylene.

[0048] In this invention, the phenyl trifunctional epoxy monomer is prepared by the following method:

[0049] S1. The alkenyl-alkoxyphenol having the structure shown in formula (2) is hydrolyzed in the presence of a catalyst and an organosilane compound and then purified to obtain the first intermediate product having the structure shown in formula (3).

[0050] S2. The first intermediate product is purified by condensation reaction with an alkenyl halide compound having the structure shown in formula (4) in the presence of an alkaline compound and a phase transfer catalyst to obtain a second intermediate product having the structure shown in formula (5).

[0051] S3. The second intermediate product is oxidized in the presence of an oxidant and then purified to obtain a phenyl trifunctional epoxy monomer.

[0052]

[0053] In formula (2), R1 and R4 are each independently a C1 to C5 alkylene group;

[0054] In formula (3), R1 is a C1 to C5 alkylene group;

[0055] In formula (4), R1 is a C1 to C5 alkylene group, and X is a halogen;

[0056] In formula (5), R1 and R2 are each independently selected from C1 to C5 alkylene groups.

[0057] In formulas (2), (3), (4), and (5), specific examples of the C1-C5 alkylene groups include, but are not limited to, at least one of methylene, ethylene, propylene, butylene, and pentylene. In formula (4), X is selected from at least one of chlorine, bromine, and iodine.

[0058] In this invention, the preferred molar ratio of the alkenyl-methoxyphenol, catalyst, basic compound, phase transfer catalyst, alkenyl halogenated compound, and peroxide is 1:(0.001~0.006):(1~3):(0.05~0.15):(1.5~4.5):(2.5~3.5). Based on 1 mol of alkenyl-methoxyphenol, the molar amount of the catalyst is 0.001–0.006 mol, such as 0.001 mol, 0.002 mol, 0.003 mol, 0.004 mol, 0.005 mol, 0.006 mol, or any value between them; the molar amount of the basic compound is 1–3 mol, such as 1 mol, 1.2 mol, 1.5 mol, 1.8 mol, 2.0 mol, 2.2 mol, 2.5 mol, 2.8 mol, 3.0 mol, or any value between them; the molar amount of the phase transfer catalyst is 0.05–0.15 mol, such as 0.05 mol. The amount of the organosilane compound is 0.08 mol, 0.1 mol, 0.12 mol, 0.15 mol, or any value between them; the molar amount of the alkenyl halide compound is 1.5 to 4.5 mol, such as 1.5 mol, 1.8 mol, 2.0 mol, 2.2 mol, 2.5 mol, 2.8 mol, 3.0 mol, 3.2 mol, 3.5 mol, 3.8 mol, 4.0 mol, 4.2 mol, 4.5 mol, or any value between them; the molar amount of the peroxide is 2.5 to 3.5 mol, such as 2.5 mol, 2.8 mol, 3.0 mol, 3.2 mol, 3.5 mol, or any value between them. The preferred molar ratio of the organosilane compound to the alkenyl-methoxyphenol is (200 to 3000) mL: 1 mol. Based on 1 mol of alkenyl-methoxyphenol, the amount of the organosilane compound used is 200 to 3000 mL, such as 200 mL, 500 mL, 1000 mL, 1500 mL, 2000 mL, 2500 mL, 3000 mL or any value between them.

[0059] In the preparation process of the above-mentioned phenyl trifunctional epoxy monomer, in step S1, the conditions of the hydrolysis reaction include a temperature preferably of 20-40℃, such as 20℃, 22℃, 25℃, 28℃, 30℃, 32℃, 35℃, 38℃, 40℃ or any value between them; and a time preferably of 0.5-4h, such as 0.5h, 1h, 1.5h, 2h, 2.5h, 3h, 3.5h, 4h or any value between them.

[0060] In the preparation process of the above-mentioned phenyl trifunctional epoxy monomer, in step S1, the hydrolysis reaction is preferably carried out as follows: alkenyl-alkoxyphenol and the catalyst are dissolved in solvent 1, an organosilane compound is slowly added dropwise, the temperature is controlled at 20–40°C, and the reaction is stirred for 0.5–4 hours. Solvent 1 is preferably toluene and / or xylene. Based on the amount of 0.1 mol of alkenyl-alkoxyphenol used, the amount of solvent 1 can be 50–200 mL, such as 50 mL, 80 mL, 100 mL, 120 mL, 150 mL, 180 mL, 200 mL, or any value between them.

[0061] In the preparation process of the above-mentioned phenyl trifunctional epoxy monomer, in step S1, the purification method can be to extract the obtained product with dichloromethane and water, distill it under reduced pressure, dissolve it in tetrahydrofuran, add it to 1-4 mol / L hydrochloric acid solution under nitrogen protection, stir the reaction at room temperature for 10-30 min, extract it with dichloromethane and water, and dry the extract phase by reduced pressure distillation.

[0062] In the preparation process of the above-mentioned phenyl trifunctional epoxy monomer, in step S1, the alkenyl-alkoxyphenol only needs to have the structure shown in formula (2), wherein R1 is a C1 to C5 alkylene group, specifically at least one of methylene, ethylene, propylene, butylene, and pentylene. From the perspective of readily available raw materials, the alkenyl-alkoxyphenol is particularly preferably 4-allyl-2-methoxyphenol.

[0063] In the preparation process of the above-mentioned phenyl trifunctional epoxy monomer, in step S2, the conditions of the condensation reaction include a temperature preferably of 60-80℃, such as 60℃, 62℃, 65℃, 68℃, 70℃, 72℃, 75℃, 78℃, 80℃ or any value between them; and a time preferably of 4-12h, such as 4h, 4.5h, 5h, 5.5h, 6h, 6.5h, 7h, 8h, 9h, 10h, 11h, 12h or any value between them.

[0064] In the preparation of the above-mentioned phenyl trifunctional epoxy monomer, in step S2, the condensation reaction is preferably carried out as follows: the first intermediate product is dissolved in solvent 2, an alkaline compound is added to provide an alkaline environment, a phase transfer catalyst is added, and the mixture is heated to 60–80°C under a nitrogen atmosphere, stirred for 10–60 min, an alkenyl halogenated compound is slowly added dropwise, and the reaction is continued for 4–12 h. Solvent 2 is preferably at least one of acetone, methyl ethyl ketone, and methyl isopropanone. Based on the amount of 0.1 mol of alkenyl-alkoxyphenol used, the amount of solvent 2 can be 100–300 mL, such as 100 mL, 120 mL, 150 mL, 180 mL, 200 mL, 220 mL, 250 mL, 280 mL, 300 mL, or any value between them.

[0065] In the preparation process of the above-mentioned phenyl trifunctional epoxy monomer, in step S2, the purification method can be to extract the obtained product with ethyl acetate and water, and then dry the extract phase by vacuum distillation.

[0066] In the preparation process of the above-mentioned phenyl trifunctional epoxy monomer, in step S3, the conditions of the oxidation reaction include a temperature preferably of 0 to 60°C, such as 0°C, 5°C, 10°C, 20°C, 30°C, 40°C, 50°C, 60°C or any value between them; and a time preferably of 24 to 80 hours, such as 24 hours, 28 hours, 30 hours, 35 hours, 40 hours, 45 hours, 50 hours, 55 hours, 60 hours, 65 hours, 70 hours, 75 hours, 80 hours or any value between them.

[0067] In the preparation process of the above-mentioned phenyl trifunctional epoxy monomer, in step S3, the oxidation reaction is preferably carried out as follows: the second intermediate product is dissolved in solvent 3, an oxidant is added at 0-60°C, and the reaction is carried out for 24-80 hours. Solvent 3 is preferably at least one of dichloromethane, chlorobenzene, ethyl acetate, and methyl acetate. Based on the amount of 0.1 mol of alkenyl-alkoxyphenol used, the amount of solvent 3 can be 200-350 mL, 200 mL, 220 mL, 250 mL, 280 mL, 300 mL, 320 mL, 350 mL, or any value between them.

[0068] In the preparation process of the above-mentioned phenyl trifunctional epoxy monomer, in step S3, the purification method can be to extract the obtained product with sodium thiosulfate solution and saturated sodium bicarbonate solution, and the extracted phase can be dried by vacuum distillation.

[0069] In this invention, the mass ratio of the phenyl trifunctional epoxy monomer to the epoxy resin is preferably 1:(0.5-2.0), such as 1:0.5, 1:0.8, 1:1.0, 1:1.2, 1:1.5, 1:1.8, 1:2.0 or any value between them.

[0070] In this invention, the mass ratio of bisphenol F diglycidyl ether to alicyclic epoxy resin in the epoxy resin is 1:(0.1 to 0.7), such as 1:0.1, 1:0.2, 1:0.3, 1:0.4, 1:0.5, 1:0.6, 1:0.7 or any value between them.

[0071] In this invention, the equivalent ratio of epoxy groups in the epoxy resin to active functional groups in the curing agent is 1:(0.4 to 1.3), such as 1:0.4, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1.0, 1:1.1, 1:1.2, 1:1.3, or any value between them. The term "active functional group" refers to an active group capable of participating in the curing reaction.

[0072] In this invention, specific examples of the inorganic filler include, but are not limited to, at least one of the following: carbon black, silica, alumina, talc, calcium carbonate, glass microspheres, metal powder, and polytetrafluoroethylene filler. The average particle size of the inorganic filler is preferably 0.1–10 μm.

[0073] The method for preparing the high-temperature resistant bottom-filled epoxy adhesive provided by this invention includes uniformly mixing a phenyl trifunctional epoxy monomer, an epoxy resin, a toughening resin, a curing agent, a curing accelerator, a coupling agent, an inorganic filler, and optional additives to obtain the high-temperature resistant bottom-filled epoxy adhesive. The mixing method can be either adding all raw materials simultaneously and mixing them together, or adding some raw materials in any order and mixing them first, followed by adding the remaining raw materials and continuing mixing; there are no particular limitations.

[0074] In a preferred embodiment, the mixing method involves uniformly mixing a phenyl trifunctional epoxy monomer, epoxy resin, toughening resin, curing agent, curing accelerator, coupling agent, and optional additives to obtain an epoxy resin composite; then adding inorganic fillers to the epoxy resin composite and continuing to mix uniformly, passing the mixture through a three-roll mill and grinding it 1 to 5 times, then transferring it to a dual planetary hybrid stirring tank and continuing to stir for 20 to 40 minutes. When the stirring time reaches 1 / 3 to 2 / 3 of the total stirring time, the wall is scraped. Finally, the resulting mixture is subjected to vacuum degassing treatment, filtered, and discharged to obtain a high-temperature resistant bottom-filling epoxy adhesive.

[0075] The present invention will be described in detail below through specific embodiments.

[0076] In the following examples and comparative examples, the parts of raw materials refer to parts by weight.

[0077] The raw materials used in the following preparation examples, embodiments, and comparative examples are as follows:

[0078] Bisphenol F diglycidyl ether was purchased from Mitsubishi Chemical Corporation, brand name JER806, with an epoxy equivalent of 160 g / eq; alicyclic epoxy resin was purchased from Daicel Corporation, brand name Celloxide 2021P; the toughening resin was hydroxyl-terminated polybutadiene, purchased from Nippon Soda Corporation, brand name NISSO PB G 3000; the curing agent was methylhexahydrophthalic anhydride, purchased from Shin-Nippon Rikka, brand name MH 700G; the curing accelerator was 1,8-diazabicyclo[5.4.0]undec-7-ene, purchased from San-Apro Corporation, brand name DBU; the silane coupling agent was γ-(2,3-epoxypropoxy)propyltrimethoxysilane, purchased from Shin-Etsu Chemical Corporation, Japan. Chemical Company, grade KBM-403; silica particles are graded spherical silica particles with an average particle size of 5 μm; carbon black is purchased from Cabot Corporation, grade BLACK PEARLS1000.

[0079] Preparation Example 1

[0080] Preparation of phenyl trifunctional epoxy monomers:

[0081] S1. Dissolve 16.42 g (0.1 mol) of 4-allyl-2-methoxyphenol and 0.041 g (0.00023 mol) of tris(pentafluorophenyl)borane in 150 mL of toluene. Slowly add 50 mL of triethylsilane, and stir the reaction under nitrogen protection at 25 °C for 40 min. Extract three times with dichloromethane and water. Distill the organic phase under reduced pressure and then dissolve it in tetrahydrofuran. Add the solution to 2 mol / L hydrochloric acid under nitrogen protection and stir the reaction at room temperature for 20 min. Extract three times with dichloromethane and water, dry, and distill under reduced pressure to obtain the first intermediate product in solid form.

[0082] S2. Dissolve the first intermediate obtained in step S1 in 200 mL of acetone, add 31.8 g (0.3 mol) of sodium carbonate to provide an alkaline environment, add 2.9 g (0.011 mol) of 18-crown ether-6, heat to 75 °C under a nitrogen atmosphere, stir for 30 min, slowly add 36.3 g (0.3 mol) of allyl bromide, react for another 8 h, extract with ethyl acetate and water, dry, distill under reduced pressure and purify to obtain a white liquid second intermediate.

[0083] S3. Dissolve the second intermediate obtained in step S2 in 200 mL of dichloromethane, add 51.78 g (0.3 mol) of m-chloroperoxybenzoic acid at 40 °C, stir and react for 48 h, extract with 10% sodium thiosulfate solution and saturated sodium bicarbonate solution, dry, and distill under reduced pressure to obtain a yellow viscous product, which is the 1,2,4-phenyl trifunctional epoxy monomer, denoted as METG-1, with a yield of 85.87%.

[0084] The infrared spectrum of the 1,2,4-phenyl trifunctional epoxy monomer is shown below. Figure 1 .from Figure 1 It can be seen that 1495cm -1 The absorption peaks at 823 cm⁻¹ are on the benzene ring. -1 The left and right positions correspond to the Ar-H bending vibrations on the benzene ring, 3000 cm. -1 The absorption peaks at the left and right are the CH stretching vibration absorption peaks on the alkyl chain, at 1250 cm⁻¹. -1 The absorption peaks appearing on the left and right are due to the stretching vibration of the alkoxy group (CO), at 910 cm⁻¹. -1 The absorption peaks at the left and right correspond to epoxy groups, 3500 cm⁻¹ -1 The hydroxyl absorption peaks corresponding to the left and right positions disappear. From Figure 1 Infrared spectroscopy results confirm the successful synthesis of the 1,2,4-phenyl trifunctional epoxy monomer.

[0085] Preparation Example 2

[0086] Preparation of phenyl trifunctional epoxy monomers:

[0087] S1. Dissolve 16.42 g (0.1 mol) of 4-allyl-2-methoxyphenol and 0.0174 g (0.0001 mol) of tris(pentafluorophenyl)borane in 50 mL of xylene, slowly add 263 mL of trimethylsilane, and stir the reaction under nitrogen protection at 20 °C for 0.5 h. Extract three times with dichloromethane and water, distill the organic phase under reduced pressure, dissolve it in tetrahydrofuran, add it to 1 mol / L hydrochloric acid solution under nitrogen protection, stir the reaction at room temperature for 10 min, extract three times with dichloromethane and water, dry, and distill under reduced pressure to obtain the first intermediate product in solid form.

[0088] S2. Dissolve the first intermediate obtained in step S1 in 100 mL of acetone, add 10.6 g (0.1 mol) of sodium carbonate to provide an alkaline environment, add 1.1 g (0.005 mol) of 15-crown ether-5, heat to 60 °C under a nitrogen atmosphere, stir for 30 min, slowly add 13.01 g (0.17 mol) of allyl chloride, react for another 4 h, extract with ethyl acetate and water, dry, distill under reduced pressure and purify to obtain a white liquid second intermediate.

[0089] S3. Dissolve the second intermediate obtained in step S2 completely in 350 mL of dichloromethane, add 60.4 g (0.35 mol) of m-chloroperoxybenzoic acid at 0 °C, stir and react for 24 h, extract with 10% sodium thiosulfate solution and saturated sodium bicarbonate solution, dry and distill under reduced pressure to obtain a yellow viscous product, which is the 1,2,4-phenyl trifunctional epoxy monomer, denoted as METG-2, with a yield of 57.3%.

[0090] Preparation Example 3

[0091] Preparation of phenyl trifunctional epoxy monomers:

[0092] S1. Dissolve 16.42 g (0.1 mol) of 4-allyl-2-methoxyphenol and 0.104 g (0.0006 mol) of tris(pentafluorophenyl)borane in 200 mL of xylene, slowly add 40 mL of polymethylsiloxane, and stir the reaction under nitrogen protection at 35 °C for 4 h. Extract three times with dichloromethane and water, distill the organic phase under reduced pressure, dissolve it in tetrahydrofuran, add it to 3 mol / L hydrochloric acid solution under nitrogen protection, stir the reaction at room temperature for 30 min, extract three times with dichloromethane and water, dry, and distill under reduced pressure to obtain the first intermediate product in solid form.

[0093] S2. Dissolve the first intermediate obtained in step S1 in 300 mL of acetone, add 15.9 g (0.15 mol) of sodium carbonate to provide an alkaline environment, add 4 g (0.015 mol) of 18-crown ether-6, heat to 80 °C under a nitrogen atmosphere, stir for 30 min, slowly add 52 g (0.43 mol) of allyl bromide, react for another 12 h, extract with ethyl acetate and water, dry, distill under reduced pressure and purify to obtain a white liquid second intermediate.

[0094] S3. Dissolve the second intermediate obtained in step S2 in 250 mL of ethyl acetate, add 30.6 g of 30% hydrogen peroxide (0.27 mol) at 60 °C, and stir for 80 h. Extract with 10% sodium thiosulfate solution and saturated sodium bicarbonate solution, dry, and distill under reduced pressure to obtain a yellow viscous product, which is the 1,2,4-phenyl trifunctional epoxy monomer, denoted as METG-3, with a yield of 54.65%.

[0095] Example 1: Preparation of High-Temperature Resistant Bottom-Filled Epoxy Adhesive

[0096] 15 parts METG-1, 12 parts bisphenol F diglycidyl ether (jER806), 3 parts alicyclic epoxy resin (Celloxide 2021P), 10 parts hydroxyl-terminated polybutadiene (NISSO-PB G-3000), 22 parts methylhexahydrophthalic anhydride (MH-700G), 1 part curing accelerator (DBU), 0.5 parts silane coupling agent (KBM-403), and 0.5 parts carbon black (BLACKPEARLS1000) were added to a dispersion mixing device and mixed evenly to obtain an epoxy resin composite. Then, 60 parts of spherical silica particles (average particle size 5μm) were added to the above epoxy resin composite and mixed evenly. After passing through a three-roll mill, the mixture was ground three times. Then, it was transferred to a dual planetary hybrid stirring kettle and stirred for 30 minutes. When the stirring time reached 1 / 3 of the total stirring time, the wall was scraped. Finally, the resulting mixture was degassed under vacuum, filtered, and discharged to obtain a high-temperature resistant bottom-filled epoxy adhesive.

[0097] Example 2: Preparation of High-Temperature Resistant Bottom-Filled Epoxy Adhesive

[0098] Ten parts of METG-1, eight parts of bisphenol F diglycidyl ether (jER806), two parts of alicyclic epoxy resin (Celloxide2021P), ten parts of hydroxyl-terminated polybutadiene (NISSOPB G3000), fourteen parts of methylhexahydrophthalic anhydride (MH700G), one part of curing accelerator (DBU), 0.5 parts of silane coupling agent (KBM-403), and 0.5 parts of carbon black (BLACK PEARLS1000) were added to a dispersion mixing device and mixed evenly to obtain an epoxy resin composite. Then, 60 parts of spherical silica particles (average particle size 5μm) were added to the above epoxy resin composite and mixed evenly. After passing through a three-roll mill, the mixture was ground three times. Then, it was transferred to a dual planetary hybrid stirring kettle and stirred for 30 minutes. When the stirring time reached 1 / 3 of the total stirring time, the wall was scraped. Finally, the resulting mixture was degassed under vacuum, filtered, and discharged to obtain a high-temperature resistant bottom-filled epoxy adhesive.

[0099] Example 3: Preparation of High-Temperature Resistant Bottom-Filled Epoxy Adhesive

[0100] 20 parts METG-1, 16 parts bisphenol F diglycidyl ether (jER806), 4 parts alicyclic epoxy resin (Celloxide 2021P), 10 parts hydroxyl-terminated polybutadiene (NISSO-PB G-3000), 29 parts methylhexahydrophthalic anhydride (MH-700G), 1 part curing accelerator (DBU), 0.5 parts silane coupling agent (KBM-403), and 0.5 parts carbon black (BLACKPEARLS1000) were added to a dispersion mixing device and mixed evenly to obtain an epoxy resin composite. Then, 60 parts of spherical silica particles (average particle size 5μm) were added to the above epoxy resin composite and mixed evenly. After passing through a three-roll mill, the mixture was ground three times. Then, it was transferred to a dual planetary hybrid stirring kettle and stirred for 30 minutes. When the stirring time reached 1 / 3 of the total stirring time, the wall was scraped. Finally, the resulting mixture was degassed under vacuum, filtered, and discharged to obtain a high-temperature resistant bottom-filled epoxy adhesive.

[0101] Example 4: Preparation of High-Temperature Resistant Bottom-Filled Epoxy Adhesive

[0102] 18 parts METG-1, 4 parts bisphenol F diglycidyl ether (jER806), 4 parts alicyclic epoxy resin (Celloxide2021P), 10 parts hydroxyl-terminated polybutadiene (NISSO-PB G-3000), 26 parts methylhexahydrophthalic anhydride (MH-700G), 1 part curing accelerator (DBU), 0.5 parts silane coupling agent (KBM-403), and 0.5 parts carbon black (BLACK PEARLS1000) were added to a dispersion mixing device and mixed evenly to obtain an epoxy resin composite. Then, 60 parts of spherical silica particles (average particle size 5μm) were added to the above epoxy resin composite and mixed evenly. After passing through a three-roll mill, the mixture was ground three times. Then, it was transferred to a dual planetary hybrid stirring kettle and stirred for 30 minutes. When the stirring time reached 1 / 3 of the total stirring time, the wall was scraped. Finally, the resulting mixture was degassed under vacuum, filtered, and discharged to obtain a high-temperature resistant bottom-filled epoxy adhesive.

[0103] Example 5: Preparation of High-Temperature Resistant Bottom-Filled Epoxy Adhesive

[0104] 12 parts METG-1, 10 parts bisphenol F diglycidyl ether (jER806), 2 parts alicyclic epoxy resin (Celloxide 2021P), 10 parts hydroxyl-terminated polybutadiene (NISSO-PB G-3000), 20 parts methylhexahydrophthalic anhydride (MH-700G), 1 part curing accelerator (DBU), 0.5 parts silane coupling agent (KBM-403), and 0.5 parts carbon black (BLACKPEARLS1000) were added to a dispersion mixing device and mixed evenly to obtain an epoxy resin composite. Then, 60 parts of spherical silica particles (average particle size 5μm) were added to the above epoxy resin composite and mixed evenly. After passing through a three-roll mill, the mixture was ground three times. Then, it was transferred to a dual planetary hybrid stirring kettle and stirred for 30 minutes. When the stirring time reached 1 / 3 of the total stirring time, the wall was scraped. Finally, the resulting mixture was degassed under vacuum, filtered, and discharged to obtain a high-temperature resistant bottom-filled epoxy adhesive.

[0105] Example 6: Preparation of High-Temperature Resistant Bottom-Filled Epoxy Adhesive

[0106] 20 parts METG-1, 7 parts bisphenol F diglycidyl ether (jER806), 3 parts alicyclic epoxy resin (Celloxide2021P), 10 parts hydroxyl-terminated polybutadiene (NISSO-PB G-3000), 20 parts methylhexahydrophthalic anhydride (MH-700G), 1 part curing accelerator (DBU), 0.5 parts silane coupling agent (KBM-403), and 0.5 parts carbon black (BLACK PEARLS1000) were added to a dispersion mixing device and mixed evenly to obtain an epoxy resin composite. Then, 60 parts of spherical silica particles (average particle size 5μm) were added to the above epoxy resin composite and mixed evenly. After passing through a three-roll mill, the mixture was ground three times. Then, it was transferred to a dual planetary hybrid stirring kettle and stirred for 30 minutes. When the stirring time reached 1 / 3 of the total stirring time, the wall was scraped. Finally, the resulting mixture was degassed under vacuum, filtered, and discharged to obtain a high-temperature resistant bottom-filled epoxy adhesive.

[0107] Example 7: Preparation of High-Temperature Resistant Bottom-Filled Epoxy Adhesive

[0108] 15 parts METG-1, 30 parts bisphenol F diglycidyl ether (jER806), 10 parts hydroxyl-terminated polybutadiene (NISSO-PB G-3000), 29 parts methylhexahydrophthalic anhydride (MH-700G), 1 part curing accelerator (DBU), 0.5 parts silane coupling agent (KBM-403), and 0.5 parts carbon black (BLACK PEARLS1000) were added to a dispersion mixing device and mixed evenly to obtain an epoxy resin composite. Then, 60 parts of spherical silica particles (average particle size 5μm) were added to the above epoxy resin composite and mixed evenly. After passing through a three-roll mill, the mixture was ground three times. Then, it was transferred to a dual planetary hybrid stirring kettle and stirred for 30 minutes. When the stirring time reached 1 / 3 of the total stirring time, the wall was scraped. Finally, the resulting mixture was degassed under vacuum, filtered, and discharged to obtain a high-temperature resistant bottom-filled epoxy adhesive.

[0109] Example 8

[0110] A high-temperature resistant underfill epoxy adhesive was prepared according to the method of Example 1, except that METG-1 was replaced with the same amount of METG-2 by weight, while the other conditions remained unchanged, to obtain the high-temperature resistant underfill epoxy adhesive.

[0111] Example 9

[0112] A high-temperature resistant underfill epoxy adhesive was prepared according to the method of Example 1, except that METG-1 was replaced with the same amount of METG-3 by weight, while the other conditions remained unchanged, to obtain the high-temperature resistant underfill epoxy adhesive.

[0113] Comparative Example 1

[0114] A high-temperature resistant underfill epoxy adhesive was prepared according to the method of Example 1, except that 0 parts of METG-1, 27 parts of bisphenol F diglycidyl ether (jER806), 3 parts of alicyclic epoxy resin (Celloxide2021P), and 16 parts of methylhexahydrophthalic anhydride (MH-700G) were added, while the other conditions remained unchanged, to obtain a reference underfill epoxy adhesive.

[0115] Comparative Example 2

[0116] A high-temperature resistant underfill epoxy adhesive was prepared according to the method of Comparative Example 1, except that 30 parts of bisphenol F diglycidyl ether (jER806) and 0 parts of alicyclic epoxy resin (Celloxide 2021P) were added, while the other conditions remained unchanged, to obtain a reference underfill epoxy adhesive.

[0117] Comparative Example 3

[0118] A high-temperature resistant underfill epoxy adhesive was prepared according to the method of Example 1, except that bisphenol F diglycidyl ether was replaced with the same amount of alicyclic epoxy resin, while the other conditions remained unchanged, to obtain a reference underfill epoxy adhesive.

[0119] Test case

[0120] (1) Glass transition temperature: Dynamic thermomechanical analysis was used to determine the change of loss factor (tanδ) with temperature in the temperature range of -40 to 250℃ under liquid nitrogen atmosphere and thin film stretching mode. The heating rate was 10℃ / min and the test frequency was 10Hz to determine the glass transition temperature of the resin composition after curing. The sample size was 30×4×2mm. 3 The results are shown in Table 1.

[0121] (2) Viscosity: The viscosity of the bottom-filled epoxy adhesives obtained in each embodiment and comparative example was tested using a HAAKE rheometer. A 20mm flat rotor was used, the test temperature was 25℃, and the rotation speed was 40s. -1 The average value of the three sets of parallel data was taken as the final viscosity, and the results are shown in Table 1.

[0122] (3) Adhesive strength: Apply 0.4mg of adhesive to the PC board, attach a 1mm silicon chip on it, and then cure it. After curing, use DAGE4000 to test the thrust to determine the adhesive strength. The results are shown in Table 1.

[0123] Table 1

[0124]

[0125]

[0126] As can be seen from the results in Table 1, the present invention combines a phenyl trifunctional epoxy monomer with an epoxy resin that includes at least bisphenol F diglycidyl ether to obtain an underfilled epoxy adhesive, which can improve the heat resistance of the underfilled epoxy adhesive after curing while achieving low viscosity and good flowability.

[0127] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention.

Claims

1. A high-temperature resistant bottom-filled epoxy adhesive, characterized in that, The high-temperature resistant bottom-filling epoxy adhesive contains a phenyl trifunctional epoxy monomer, epoxy resin, toughening resin, curing agent, curing accelerator, coupling agent, inorganic filler, and optional additives; the phenyl trifunctional epoxy monomer content is 10-20 parts by weight, the epoxy resin content is 10-30 parts by weight, the toughening resin content is 5-20 parts by weight, the curing agent content is 14-30 parts by weight, the curing accelerator content is 0.05-3 parts by weight, the coupling agent content is 0.1-3 parts by weight, and the inorganic filler content is 50-80 parts by weight. The phenyl trifunctional epoxy monomer has the structure shown in formula (1): Equation (1), In formula (1), R1, R2 and R3 are each independently a C1~C5 alkylene group; The epoxy resin is a mixture of bisphenol F diglycidyl ether and alicyclic epoxy resin.

2. The high-temperature resistant bottom-filling epoxy adhesive according to claim 1, characterized in that, The content of the auxiliary agent is 0.1 to 10 parts by weight.

3. The high-temperature resistant bottom-filling epoxy adhesive according to claim 1, characterized in that, The phenyl trifunctional epoxy monomer was prepared by the following method: S1. The alkenyl-alkoxyphenol having the structure shown in formula (2) is hydrolyzed in the presence of a catalyst and an organosilane compound and then purified to obtain the first intermediate product having the structure shown in formula (3). S2. The first intermediate product is purified by condensation reaction with an alkenyl halide compound having the structure shown in formula (4) in the presence of an alkaline compound and a phase transfer catalyst to obtain a second intermediate product having the structure shown in formula (5). S3. The second intermediate product is oxidized in the presence of an oxidant and then purified to obtain a phenyl trifunctional epoxy monomer. Equation (2), Equation (3), Equation (4), Equation (5), In formula (2), R1 and R4 are each independently a C1~C5 alkylene group; In formula (3), R1 is a C1~C5 alkylene group; In formula (4), R2 is a C1~C5 alkylene group, and X is a halogen; In formula (5), R1 and R2 are each independently C1 to C5 alkylene groups.

4. The high-temperature resistant bottom-filling epoxy adhesive according to claim 3, characterized in that, The ratio of the amount of alkenyl-alkoxyphenol, catalyst, organosilanes, basic compounds, phase transfer catalyst, alkenyl halogenated compounds and oxidant is 1 mol:(0.001~0.006) mol:(200~3000) mL:(1~3) mol:(0.05~0.15) mol:(1.5~4.5) mol:(2.5~3.5) mol.

5. The high-temperature resistant bottom-filling epoxy adhesive according to claim 3, characterized in that, The catalyst is selected from at least one of tris(pentafluorophenyl)borane, triphenylmethyltetra(pentafluorophenyl)borate, dimethylbis(octadecylbenzene-1,4-diaminotetra(pentafluorophenyl)borate, N,N-dimethylphenylammoniumtetra(pentafluorophenyl)borate, N,N-bis(octadecylbenzene-1,4-diaminotetra(pentafluorophenyl)borate, N-methyldiphenylammoniumtetra(pentafluorophenyl)borate, and potassium tetra(pentafluorophenyl)borate. The organosilane compound is selected from at least one of trimethylsilane, triethylsilane, triisopropylsilane, tributylsilane, and polymethylsiloxane; The alkaline compound is selected from at least one of potassium hydroxide, sodium hydroxide, magnesium hydroxide, calcium hydroxide, barium hydroxide, sodium carbonate, and potassium carbonate. The phase transfer catalyst is selected from at least one of cyclic crown ethers, polyethers, and ammonium compounds; The alkenyl halogenated compound is selected from at least one of allyl bromide, allyl chloride, allyl iodide, bromobutene, bromopentene, bromohexene, bromoheptene, and chlorobutene; The oxidant is selected from at least one of m-chloroperoxybenzoic acid, hydrogen peroxide, peroxybenzoic acid, peracetic acid, and peroxyformic acid.

6. The high-temperature resistant bottom-filling epoxy adhesive according to claim 1, characterized in that, The mass ratio of the phenyl trifunctional epoxy monomer to the epoxy resin is 1:(0.5~2.0); the mass ratio of bisphenol F diglycidyl ether to the alicyclic epoxy resin in the epoxy resin is 1:(0.1~0.7); and the equivalent ratio of the epoxy group in the epoxy resin to the active functional group in the curing agent is 1:(0.4~1.3).

7. The high-temperature resistant bottom-filling epoxy adhesive according to claim 1, characterized in that, The toughening resin is selected from at least one of liquid nitrile rubber, liquid polybutadiene, liquid polysulfide rubber, chloroprene rubber, cashew shell liquid modified phenolic resin, polyester resin, epoxy resin active toughening agent, SBS thermoplastic elastomer, polyvinyl alcohol methyl acetal, polyethersulfone, polyimide, polyether ether ketone, polyether diol and polyether triol.

8. The high-temperature resistant bottom-filling epoxy adhesive according to claim 1, characterized in that, The curing agent is selected from at least one of amine curing agents, acid anhydride curing agents, phenolic curing agents, imidazole curing agents, and latent curing agents; The curing accelerator is selected from at least one of imidazole compounds, amine compounds, and phosphorus compounds; The coupling agent is selected from at least one of γ-methacryloxypropyltrimethoxysilane, vinyltris(β-methoxyethoxy)silane, vinyltrimethoxysilane, vinyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, anilinemethyltriethoxysilane, γ-(2,3-epoxypropoxy)propyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and γ-ureapropyltriethoxysilane. The inorganic filler is selected from at least one of carbon black, silica, alumina, talc, calcium carbonate, glass microspheres, metal powder and polytetrafluoroethylene filler; The additives are selected from at least one of stabilizers, polymerization inhibitors, antioxidants, flame retardants, diluents, adhesion promoters, dyes, pigments, defoamers, leveling agents, homogenizers, and ion trapping agents.

9. A method for preparing the high-temperature resistant bottom-filled epoxy adhesive according to any one of claims 1 to 8, characterized in that, The method involves uniformly mixing a phenyl trifunctional epoxy monomer, an epoxy resin, a toughening resin, a curing agent, a curing accelerator, a coupling agent, and inorganic fillers, along with optional additives, to obtain a high-temperature resistant bottom-filled epoxy adhesive.

10. The application of the high-temperature resistant bottom-filling epoxy adhesive according to any one of claims 1 to 8 in the chip and PCB substrate packaging process.

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