Sealing material for EBGA packaging and preparation method thereof

Abstract

The invention discloses a sealing material for EBGA packaging and a preparation method thereof, and relates to the technical field of sealing materials. The sealing material is prepared from the following raw materials in parts by weight: 80 to 100 parts of modified epoxy resin, 30 to 40 parts of bismaleimide resin, 8 to 10 parts of curing agent, 0.1 to 0.5 part of curing accelerator, 1 to 3 parts of flame retardant and 10 to 20 parts of inorganic filler, the preparation method comprises the following steps: reacting 2, 2 '-diallyl bisphenol A with epoxy chloropropane to prepare an intermediate 1, then carrying out hydrosilylation reaction on the intermediate 1 and high-hydrogen-content silicone oil to prepare an intermediate 2, and finally reacting the intermediate 2 with thermoplastic phenolic resin to obtain the modified epoxy resin. The sealing material prepared by the invention has high toughness and low water absorption.

Description

Technical Field

[0001] The invention relates to the technical field of sealing materials, and in particular to a sealing material for EBGA packaging and a preparation method thereof. Background Art

[0002] Modern microelectronics technology is developing rapidly towards ultra-large scale, ultra-high speed, high density, high power, high precision and multi-function at an astonishing speed. The microelectronics industry has become one of the industries that have a significant impact on the country's economy, politics, society, security and culture. Integrated circuits are the core of microelectronics technology. Among the three pillars of the integrated circuit industry (integrated circuit design, integrated circuit manufacturing and integrated circuit packaging), integrated circuit packaging plays an important role in promoting the rapid development of the integrated circuit industry. With the further miniaturization and miniaturization of package size, many new packaging technologies and packaging forms have emerged. Among them, the most representative packaging technologies are ball grid array (BGA), flip chip (FC) and multi-chip module (MCMS).

[0003] For integrated circuits, electronic packaging materials refer to their packaging (sealed) bodies. Packaging measures provide physical support and protection for the chip, preventing it from being polluted and eroded by impurities, water vapor and various chemical atmospheres in the atmosphere, so that the integrated circuit chip can function under stable conditions. In addition, packaging materials play a vital role in key performances such as the thermal performance and even reliability of devices and circuits.

[0004] Epoxy resin has excellent mechanical, dielectric, corrosion resistance, and bonding properties, small curing shrinkage and linear expansion coefficient, good dimensional stability, good processability, and excellent comprehensive performance, so it is widely used in the field of electronic appliances. However, due to its high rigidity modulus, epoxy resin is prone to uneven heating during heat treatment and curing, resulting in a high concentration of cross-linking density in a certain part, thereby generating stress concentration. Once severe, cracking may even occur, making it difficult for packaging materials prepared from epoxy resin to achieve high elasticity. Therefore, in order to further improve the performance of epoxy resin as a packaging material, it needs to be modified accordingly to meet the needs of the product.

[0005] A Chinese invention patent with publication number CN108485193A discloses a flame retardant epoxy resin composition that can be used for electronic packaging materials and a preparation method thereof. The composition and mass fraction of the composition are as follows: 18-28 parts of epoxy resin I, 22-32 parts of homemade halogen-free flame retardant epoxy resin, 3.2-12 parts of curing agent, 0.04-0.8 parts of curing accelerator, 20-35 parts of inorganic filler, and 15-30 parts of flame retardant synergist. The composition has good flame retardancy, flame retardancy durability, and heat resistance, but its toughness and water absorption are poor. Summary of the invention

[0006] In view of the deficiencies in the prior art, an object of the present invention is to provide a sealing material for EBGA packaging and a preparation method thereof.

[0007] To achieve the above object, the present invention is implemented through the following technical solutions: Modified epoxy resin: 80-100 parts, bismaleimide resin: 30-40 parts, curing agent: 8-10 parts, curing accelerator: 0.1-0.5 parts, flame retardant: 1-3 parts, inorganic filler 10-20 parts; The modified epoxy resin is prepared by the following method: S1: Under nitrogen protection, add 2,2'-diallylbisphenol A and epichlorohydrin to the reactor, stir, heat to 60-70°C, then add tetramethylammonium bromide, continue to heat to 90-100°C, react for 2-3h, cool to 80°C, slowly drop sodium hydroxide solution, continue to react for 1-2h after dropwise addition, rotary evaporate to obtain a crude product, then add toluene and sodium hydroxide solution, react at 80-90°C for 2-3h, and post-treat to obtain intermediate 1; S2: Under nitrogen protection, add toluene, high hydrogen silicone oil and intermediate 1 into the reactor, stir, heat to 70-110°C, slowly drop chloroplatinic acid-triphenylphosphine complex, react for 2-6 hours, and post-treat to obtain intermediate 2; S3: Under nitrogen protection, add toluene, intermediate 2, and thermoplastic phenolic resin into the reactor, stir, heat to 100-120°C, add triphenylphosphine and react for 6-8h, then cure at 150°C for 2h to obtain modified epoxy resin.

[0008] In the step S1, the mass ratio of 2,2'-diallylbisphenol A, epichlorohydrin and tetramethylammonium bromide is (5-8):(50-80):(0.1-0.3).

[0009] In the step S2, the mass ratio of toluene, high hydrogen-containing silicone oil, intermediate 1 and chloroplatinic acid-triphenylphosphine complex is 30:(8-10):(5-7):(0.1-0.3).

[0010] In the step S3, the mass ratio of toluene, intermediate 2, thermoplastic phenolic resin and triphenylphosphine is 20:(3-7):(1-9):(0.1-0.3).

[0011] The curing agent is a combination of one or more of methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride and pyromellitic anhydride.

[0012] The curing accelerator is one of N,N-dimethylethanolamine, bisphenol A and resorcinol.

[0013] The flame retardant is one of tributyl phosphate, tri(2-ethylhexyl) phosphate, and tri(2-chloroethyl) phosphate.

[0014] The inorganic filler is one or a combination of mica powder, calcium carbonate and barium sulfate.

[0015] A method for preparing a sealing material for EBGA packaging comprises the following steps: (1) Weigh by weight: modified epoxy resin: 80-100 parts, bismaleimide resin: 30-40 parts, curing agent: 8-10 parts, curing accelerator: 0.1-0.5 parts, flame retardant: 1-3 parts, inorganic filler: 10-20 parts; (2) The above raw materials are pre-mixed according to the mass ratio, and after being mixed evenly, the materials are melted, extruded and mixed, tableted and cooled, and then sheared and crushed by a high-speed mixer, and finally sieved to obtain the sealing material.

[0016] Due to the adoption of the above technical solution, the beneficial effects of the present invention include: (1) The present invention prepares intermediate 1 by reacting 2,2'-diallyl bisphenol A and epichlorohydrin, then prepares intermediate 2 by hydrosilylation reaction of intermediate 1 and high hydrogen-containing silicone oil, and finally reacts intermediate 2 with thermoplastic phenolic resin to obtain modified epoxy resin.

[0017] (2) The modified epoxy resin prepared by the present invention improves the weather resistance of the epoxy resin by introducing Si-O bonds. Since the Si-O bonds are highly polar and have a significant tendency to ionize, they can effectively improve the stability of the material to oxidation. At the same time, the flexible Si-O bonds are introduced inside the epoxy. The Si-O bonds can make the polymer chain segments rotate more easily, which can eliminate some internal stresses, thereby improving the fracture toughness of the epoxy resin cured product. In addition, the bond energy of Si-O is much greater than that of CC bonds, which can improve the heat resistance of the epoxy resin. In addition, the organic silicon containing Si-H bonds undergoes a silylation reaction with the epoxy resin with double bonds to generate Si-C bonds in the modified resin with better hydrolysis stability than Si-OC, thereby improving the water resistance of the modified epoxy resin.

[0018] (3) The modified epoxy resin prepared by the present invention is prepared by adding a thermoplastic phenolic resin curing agent. The phenolic hydroxyl group in the curing agent undergoes a ring-opening reaction with the epoxy group, and the molecular weight is enlarged by the epoxy ring-opening branching curing agent. Finally, a three-dimensional network structure is formed, forming a cured body with certain mechanical properties, thereby improving the toughness of the epoxy resin. DETAILED DESCRIPTION

[0019] The invention will be further described below in conjunction with the embodiments, but the invention is not limited to these embodiments.

[0020] Example 1 Preparation of modified epoxy resin: S1: Under nitrogen protection, add 50g 2,2'-diallyl bisphenol A and 500g epichlorohydrin to the reactor, stir, heat to 60°C, then add 1g tetramethylammonium bromide, continue to heat to 90°C, react for 3h, cool to 80°C, slowly drop 80g 48wt% sodium hydroxide solution, drop for 1h, continue to react for 1h after drop, filter to remove solid, rotary evaporate at 70°C for 4h to obtain a crude product, then add 200g toluene and 100g 5wt% sodium hydroxide solution, react at 80°C for 3h, separate the liquids, then add 80g toluene, wash with deionized water until the pH is neutral, rotary evaporate at 90°C for 1h to obtain intermediate 1, the reaction equation is as follows: S2: Under nitrogen protection, add 300g toluene, 80g high hydrogen silicone oil and 50g intermediate 1 to the reactor, stir, heat to 70°C, slowly drop 1g chloroplatinic acid-triphenylphosphine complex, drop for 2min, react for 6h, and distill at 90°C under reduced pressure for 1h to obtain intermediate 2. The reaction equation is as follows: S3: Under nitrogen protection, add 200g toluene, 30g intermediate 2, and 10g thermoplastic phenolic resin into the reactor, stir, heat to 100°C, add 1g triphenylphosphine and react for 8h, then cure at 150°C for 2h to obtain modified epoxy resin. The reaction equation is as follows: in represent: —R—stands for: Among them, m, n, p, q, s, t are natural numbers; The reaction equation of step S3 is only a schematic diagram of the reaction process. The actual reaction process is very complicated. The reaction principle is the reaction between phenolic hydroxyl and epoxy groups. The dotted line drawn in step S3 represents that the arrangement order of the monomers is uncertain.

[0021] Example 2 Preparation of modified epoxy resin: S1: Under nitrogen protection, add 70g 2,2'-diallyl bisphenol A and 700g epichlorohydrin to the reactor, stir, heat to 65°C, then add 2g tetramethylammonium bromide, continue to heat to 95°C, react for 2.5h, cool to 80°C, slowly drop 100g 48wt% sodium hydroxide solution, drop for 1h, continue to react for 1.5h after drop, filter to remove solid, rotary evaporate at 70°C for 3h to obtain a crude product, then add 250g toluene and 125g 5wt% sodium hydroxide solution, react at 85°C for 2.5h, separate, then add 80g toluene, wash with deionized water until pH is neutral, rotary evaporate at 90°C for 2h to obtain intermediate 1; S2: Under nitrogen protection, add 300g toluene, 90g high hydrogen silicone oil and 60g intermediate 1 into the reactor, stir, heat to 90°C, slowly drop 2g chloroplatinic acid-triphenylphosphine complex, drop for 2min, react for 4h, and distill at 85°C under reduced pressure for 1h to obtain intermediate 2; S3: Under nitrogen protection, add 200 g toluene, 50 g intermediate 2, and 50 g thermoplastic phenolic resin into the reactor, stir, heat to 110°C, add 2 g triphenylphosphine and react for 7 h, then cure at 150°C for 2 h to obtain modified epoxy resin.

[0022] Example 3 Preparation of modified epoxy resin: S1: Under nitrogen protection, add 80g 2,2'-diallyl bisphenol A and 800g epichlorohydrin to the reactor, stir, heat to 70°C, then add 3g tetramethylammonium bromide, continue to heat to 100°C, react for 2h, cool to 80°C, slowly drop 120g 48wt% sodium hydroxide solution, drop for 1h, continue to react for 2h after drop, filter to remove solid, rotary evaporate at 90°C for 2h to obtain a crude product, then add 300g toluene and 150g 5wt% sodium hydroxide solution, react at 90°C for 2h, separate the liquids, then add 80g toluene, wash with deionized water until the pH is neutral, and rotary evaporate at 80°C for 3h to obtain intermediate 1; S2: Under nitrogen protection, add 300g toluene, 100g high hydrogen silicone oil and 70g intermediate 1 into the reactor, stir, heat to 110°C, slowly drop 3g chloroplatinic acid-triphenylphosphine complex, drop for 2min, react for 2h, and distill at 80°C under reduced pressure for 1.5h to obtain intermediate 2; S3: Under nitrogen protection, add 200 g toluene, 70 g intermediate 2, and 90 g thermoplastic phenolic resin into the reactor, stir, heat to 120°C, add 3 g triphenylphosphine and react for 6 h, then cure at 150°C for 2 h to obtain modified epoxy resin.

[0023] Example 4 Preparation of sealing material: (1) Weigh the following by weight: modified epoxy resin (prepared in Example 1): 800 g, bismaleimide resin: 300 g, curing agent (methylhexahydrophthalic anhydride): 80 g, curing accelerator (N,N-dimethylethanolamine): 1 g, flame retardant (tributyl phosphate): 10 g, inorganic filler (calcium carbonate): 100 g; (2) The above raw materials are pre-mixed according to the mass ratio for 15 minutes at a speed of 1000 r / min. After being mixed evenly, the materials are melted and extruded. The extruder temperature is 130°C and the extruder speed is 1800 r / min. After tableting, they are cooled and then sheared and crushed by a high-speed mixer at a speed of 3500 r / min. Finally, they are sieved to obtain the sealing material.

[0024] Example 5 Preparation of sealing material: (1) Weigh the following by weight: modified epoxy resin (prepared in Example 2): 900 g, bismaleimide resin: 350 g, curing agent (methyltetrahydrophthalic anhydride): 90 g, curing accelerator (bisphenol A): 3 g, flame retardant (tri(2-ethylhexyl) phosphate): 20 g, inorganic filler (barium sulfate): 150 g; (2) The above raw materials are pre-mixed according to the mass ratio for 15 minutes at a speed of 1000 r / min. After being mixed evenly, the materials are melted and extruded. The extruder temperature is 130°C and the extruder speed is 1800 r / min. After double-roll milling, they are cooled. Then, they are sheared and crushed by a high-speed mixer at a speed of 3500 r / min. Finally, they are sieved to obtain the sealing material.

[0025] Example 6 Preparation of sealing material: (1) Weigh the following by weight: modified epoxy resin (prepared in Example 3): 900 g, bismaleimide resin: 350 g, curing agent (pyromellitic anhydride): 90 g, curing accelerator (resorcinol): 3 g, flame retardant (tris(2-chloroethyl) phosphate): 20 g, inorganic filler (mica powder): 150 g; (2) The above raw materials are pre-mixed according to the mass ratio for 15 minutes at a speed of 1000 r / min. After being mixed evenly, the materials are melted and extruded. The extruder temperature is 130°C and the extruder speed is 1800 r / min. After double-roll milling, they are cooled. Then, they are sheared and crushed by a high-speed mixer at a speed of 3500 r / min. Finally, they are sieved to obtain the sealing material.

[0026] Comparative Example 1 A method for preparing a sealing material for EBGA packaging is substantially the same as that of Example 5, except that the modified epoxy resin added in step (1) is replaced by an equal weight of bisphenol A epoxy resin.

[0027] Comparative Example 2 A method for preparing a sealing material for EBGA packaging is substantially the same as that of Example 5, except that the modified epoxy resin added in step (1) is replaced by an equal weight of modified epoxy resin prepared by the following method: S1: Under nitrogen protection, add 70g 2,2'-diallyl bisphenol A and 700g epichlorohydrin to the reactor, stir, heat to 65°C, then add 2g tetramethylammonium bromide, continue to heat to 95°C, react for 2.5h, cool to 80°C, slowly drop 100g 48wt% sodium hydroxide solution, drop for 1h, continue to react for 1.5h after drop, filter to remove solid, rotary evaporate at 80°C for 3h to obtain a crude product, then add 250g toluene and 125g 5wt% sodium hydroxide solution, react at 85°C for 2.5h, separate, then add 80g toluene, wash with deionized water until pH is neutral, rotary evaporate at 90°C for 2h to obtain intermediate 1; S2: Under nitrogen protection, add 200 g toluene, 50 g intermediate 1, and 50 g thermoplastic phenolic resin into the reactor, stir, heat to 110°C, then add 2 g triphenylphosphine and react for 7 h, then cure at 150°C for 2 h to obtain modified epoxy resin.

[0028] Comparative Example 3 A method for preparing a sealing material for EBGA packaging is substantially the same as that of Example 5, except that the modified epoxy resin added in step (1) is replaced by an equal weight of modified epoxy resin prepared by the following method: S1: Under nitrogen protection, add 70g 2,2'-diallyl bisphenol A and 700g epichlorohydrin to the reactor, stir, heat to 65°C, then add 2g tetramethylammonium bromide, continue to heat to 95°C, react for 2.5h, cool to 80°C, slowly drop 100g 48wt% sodium hydroxide solution, drop for 1h, continue to react for 1.5h after drop, filter to remove solid, rotary evaporate at 80°C for 3h to obtain a crude product, then add 250g toluene and 125g 5wt% sodium hydroxide solution, react at 85°C for 2.5h, separate, then add 80g toluene, wash with deionized water until pH is neutral, rotary evaporate at 90°C for 2h to obtain intermediate 1; S2: Under nitrogen protection, add 300g toluene, 90g cyclic dimethyl polysiloxane and 60g intermediate 1 into the reactor, stir, heat to 90°C, slowly drop 2g chloroplatinic acid-triphenylphosphine complex, drop for 2min, react for 4h, and distill at 90°C under reduced pressure for 2.5h to obtain intermediate 2; S3: Under nitrogen protection, add 200g toluene, 50g intermediate 2, and 50g thermoplastic phenolic resin into the reactor, stir, heat to 110°C, then add 2g triphenylphosphine and react for 7h, then cure at 150°C for 2h to obtain modified epoxy resin.

[0029] Comparative Example 4 A method for preparing a sealing material for EBGA packaging is substantially the same as that of Example 5, except that the modified epoxy resin added in step (1) is replaced by an equal weight of modified epoxy resin prepared by the following method: S1: Under nitrogen protection, add 70g 2,2'-diallyl bisphenol A and 700g epichlorohydrin to the reactor, stir, heat to 65°C, then add 2g tetramethylammonium bromide, continue to heat to 95°C, react for 2.5h, cool to 80°C, slowly drop 100g 48wt% sodium hydroxide solution, drop for 1h, continue to react for 1.5h after drop, filter to remove solid, rotary evaporate at 80°C for 3h to obtain a crude product, then add 250g toluene and 125g 5wt% sodium hydroxide solution, react at 85°C for 2.5h, separate, then add 80g toluene, wash with deionized water until pH is neutral, rotary evaporate at 90°C for 2h to obtain intermediate 1; S2: Under nitrogen protection, add 300g toluene, 90g D4H cyclotetrasiloxane and 60g intermediate 1 into the reactor, stir, heat to 90°C, slowly drop 2g chloroplatinic acid-triphenylphosphine complex, drop for 2min, react for 4h, and distill under reduced pressure at 90°C for 2.5h to obtain intermediate 2; S3: Under nitrogen protection, add 200g toluene, 50g intermediate 2, and 50g thermoplastic phenolic resin into the reactor, stir, heat to 110°C, then add 2g triphenylphosphine and react for 7h, then cure at 150°C for 2h to obtain modified epoxy resin.

[0030] Comparative Example 5 A method for preparing a sealing material for EBGA packaging is substantially the same as that of Example 5, except that the modified epoxy resin added in step (1) is replaced by an equal weight of modified epoxy resin prepared by the following method: S1: Under nitrogen protection, add 70g 2,2'-diallyl bisphenol A and 700g epichlorohydrin to the reactor, stir, heat to 65°C, then add 2g tetramethylammonium bromide, continue to heat to 95°C, react for 2.5h, cool to 80°C, slowly drop 100g 48wt% sodium hydroxide solution, drop for 1h, continue to react for 1.5h after drop, filter to remove solid, rotary evaporate at 80°C for 3h to obtain a crude product, then add 250g toluene and 125g 5wt% sodium hydroxide solution, react at 85°C for 2.5h, separate, then add 80g toluene, wash with deionized water until pH is neutral, rotary evaporate at 90°C for 2h to obtain intermediate 1; S2: Under nitrogen protection, add 300g toluene, 90g high hydrogen silicone oil and 60g intermediate 1 into the reactor, stir, heat to 90°C, slowly drop 2g chloroplatinic acid-triphenylphosphine complex, drop for 2min, react for 4h, and distill under reduced pressure at 90°C for 2.5h to obtain intermediate 2; S3: Under nitrogen protection, add 200 g toluene, 50 g intermediate 2, and 50 g thermosetting phenolic resin into the reactor, stir, heat to 110°C, then add 2 g triphenylphosphine and react for 7 h, then cure at 150°C for 2 h to obtain modified epoxy resin.

[0031] The preparation method of thermosetting phenolic resin is as follows: Add 150g phenol, 135g formaldehyde, and 6g ammonia water into the reaction bottle, stir, and heat in a water bath. React at 50°C for 20min, then at 60°C for 1h, then raise the temperature to 76°C and react for 2h to obtain a thermosetting epoxy resin.

[0032] Comparative Example 6 A method for preparing a sealing material for EBGA packaging is substantially the same as that of Example 5, except that the modified epoxy resin added in step (1) is replaced by an equal weight of modified epoxy resin prepared by the following method: S1: Under nitrogen protection, add 70g 2,2'-diallyl bisphenol A and 700g epichlorohydrin to the reactor, stir, heat to 65°C, then add 2g tetramethylammonium bromide, continue to heat to 95°C, react for 2.5h, cool to 80°C, slowly drop 100g 48wt% sodium hydroxide solution, drop for 1h, continue to react for 1.5h after drop, filter to remove solid, rotary evaporate at 80°C for 3h to obtain a crude product, then add 250g toluene and 125g 5wt% sodium hydroxide solution, react at 85°C for 2.5h, separate, then add 80g toluene, wash with deionized water until pH is neutral, rotary evaporate at 90°C for 2h to obtain intermediate 1; S2: Under nitrogen protection, add 300g toluene, 90g high hydrogen silicone oil and 60g intermediate 1 into the reactor, stir, heat to 90°C, slowly drop 2g chloroplatinic acid-triphenylphosphine complex, drop for 2min, react for 4h, and distill under reduced pressure at 90°C for 2.5h to obtain intermediate 2; S3: Under nitrogen protection, add 200g toluene, 50g intermediate 2, and 50g o-cresol resin into the reactor, stir, heat to 110°C, then add 2g triphenylphosphine and react for 7h, then cure at 150°C for 2h to obtain modified epoxy resin.

[0033] The preparation method of o-cresol-formaldehyde resin is as follows: Add 303.5g o-cresol, 47.2g 2,6-dimethylphenol, 94.9g paraformaldehyde and 7.59g oxalic acid dihydrate into the reactor and heat at 100℃ for 6h, then add 27ml 37wt% formaldehyde solution and continue to react for 18h. Wash twice with boiling deionized water and cure at 215℃ for 2h to obtain o-cresol formaldehyde resin.

[0034] Comparative Example 7 A method for preparing a sealing material for EBGA packaging is basically the same as that of Example 5, except that the modified epoxy resin added in step (1) is replaced by an equal weight of the intermediate 2 prepared in step S2 of Example 5.

[0035] Comparative Example 8 A flame retardant epoxy resin composition that can be used for electronic packaging materials is prepared by using the raw materials and method of Example 2 in publication number CN108485193A.

[0036] Comparative Example 9 A method for preparing a sealing material for EBGA packaging is substantially the same as that of Example 5, except that the modified epoxy resin added in step (2) is replaced by an equal weight of an organosilicon-modified epoxy resin prepared by the following method: Add 75g of bisphenol A epoxy resin and 25g of polyphenylmethylethoxysilane into the reactor, stir evenly, add 0.125g of dibutyltin dilaurate, heat to 120°C and react for 6h, cool to 90°C to obtain silicone-modified epoxy resin.

[0037] The preparation method of polyphenylmethylethoxysilane is as follows: Add 120 g of phenyltriethoxysilane and 140 g of phenylmethyldiethoxysilane into the reactor, stir evenly and raise the temperature to 50°C. Add a mixture of 30 g of deionized water and 0.36 g of 36 wt% concentrated hydrochloric acid dropwise within 0.5 h. After reflux for 1 h, distill under reduced pressure to obtain polyphenylmethylethoxysilane.

[0038] The high hydrogen silicone oil used in the examples and comparative examples of the present application is Dow Corning high hydrogen silicone oil MHX-1107 (20cs); the thermoplastic phenolic resin model is PF2893, purchased from Jinan Shengquan Group Co., Ltd.; the bismaleimide resin model is PFB201, purchased from Jinan Shengquan Group Co., Ltd.; the bisphenol A type epoxy resin model is E-44, purchased from Sinopec Hunan Petrochemical Co., Ltd.; cyclic dimethyl polysiloxane is purchased from Hubei Wonder Chemical Co., Ltd.; the mica powder specification is 400 mesh.

[0039] The chloroplatinic acid-triphenylphosphine complex used in the examples and comparative examples of the present application is an isopropanol suspension with a molar concentration of 0.05 M, and the molar ratio of chloroplatinic acid to the triphenylphosphine complex is 1:1. The specific preparation method is: take 20.0 ml of a 0.1 M chloroplatinic acid isopropanol solution, add it to an equal volume and equimolar triphenylphosphine isopropanol solution, mix well, and obtain a 0.05 M chloroplatinic acid-triphenylphosphine complex.

[0040] The tensile strength and elongation at break tests were carried out according to Type 1 specimens in GB / T 528-2009, and the impact strength test was carried out according to GB / T1843-2008.

[0041] The specimens were placed in deionized boiling water at 100°C and boiled for 24 hours to test the water absorption. The test results are shown in Table 1.

[0042] Table 1 Sealing material performance test data table It can be seen from Table 1 that the sealing material prepared in the present application has good properties such as high toughness and low water absorption.

[0043] In Comparative Example 1, the modified epoxy resin is replaced with an equal weight of bisphenol A epoxy resin. From the data in Table 1, it can be seen that its impact strength is 2.35 MPa and its water absorption rate is 1.63%. Compared with the sealing material prepared in this application, its toughness and water resistance are poor.

[0044] The modified epoxy resin added in Comparative Example 2 is not grafted with silicone. From the data in Table 1, it can be seen that the tensile strength of the sealing material prepared without adding silicone is worse than that of Example 5, indicating that the addition of silicone can improve the toughness of the resin.

[0045] In Comparative Example 3, the high hydrogen silicone oil in step S2 in the preparation process of the modified epoxy resin is replaced with cyclic dimethyl polysiloxane. It can be seen from the data in Table 1 that its impact strength is 4.03 MPa and its water absorption rate is 0.9%. Compared with the sealing material prepared in this application, its toughness and water resistance are poor.

[0046] In Comparative Example 4, the high hydrogen silicone oil in step S2 in the preparation process of the modified epoxy resin is replaced with D4H cyclotetrasiloxane. It can be seen from the data in Table 1 that its impact strength is 3.78 MPa, the tensile strength is 41.28 MPa, and the water absorption rate is 1.15%. The toughness and water absorption performance of the prepared sealing material are average.

[0047] In Comparative Example 5, the thermoplastic phenolic resin in step S3 of the modified epoxy resin preparation process is replaced by a thermosetting phenolic resin. From the data in Table 1, it can be seen that the impact strength is 3.69 MPa, the tensile strength is 40.97 MPa, and the water absorption rate is 0.95%. The toughness and water absorption performance of the prepared sealing material are average.

[0048] In Comparative Example 6, the thermoplastic phenolic resin in step S3 of the modified epoxy resin preparation process is replaced with o-cresol phenolic resin. From the data in Table 1, it can be seen that the impact strength is 3.81 MPa, the tensile strength is 41.92 MPa, and the water absorption rate is 0.79%. The toughness and water absorption performance of the prepared sealing material are average.

[0049] In Comparative Example 7, the modified epoxy resin is replaced with an equal weight of the intermediate 2 prepared in step S2 of Example 5. From the data in Table 1, it can be seen that the impact strength is 3.74 MPa, the tensile strength is 39.79 MPa, and the water absorption rate is 1.02%, indicating that the toughness and water absorption performance of the sealing material prepared without curing the thermoplastic phenolic resin are average.

[0050] Comparative Example 8 is a flame retardant epoxy resin composition that can be used for electronic packaging materials, prepared using the raw materials and methods of Example 2 in Publication No. CN108485193A. It can be seen from the data in Table 1 that its impact strength is 3.55 MPa, tensile strength is 38.03 MPa, and water absorption is 1.06%. The toughness and water absorption properties of the material prepared in this application are not as good as those of this application.

[0051] Comparative Example 9 is a prepared organosilicon-modified epoxy resin. From the data in Table 1, it can be seen that its impact strength is 2.81 MPa, the tensile strength is 38.16 MPa, and the water absorption rate is 0.81%. The toughness and water absorption performance of the prepared sealing material are average.

[0052] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. However, any equivalent changes, modifications and evolutions made by ordinary technicians in the field without departing from the scope of the technical solution of the present invention by using the technical content disclosed above are all equivalent embodiments of the present invention. At the same time, any equivalent changes, modifications and evolutions made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the technical solution of the present invention.

Claims

1. A sealing material for EBGA packaging, characterized in that: The invention comprises the following raw materials in parts by weight: Modified epoxy resin: 80-100 parts, bismaleimide resin: 30-40 parts, curing agent: 8-10 parts, curing accelerator: 0.1-0.5 parts, flame retardant: 1-3 parts, inorganic filler 10-20 parts; The modified epoxy resin is prepared by the following method: S1: Under nitrogen protection, add 2,2'-diallylbisphenol A and epichlorohydrin to the reactor, stir, heat to 60-70°C, then add tetramethylammonium bromide, continue to heat to 90-100°C, react for 2-3h, cool to 80°C, slowly drop sodium hydroxide solution, continue to react for 1-2h after dropwise addition, rotary evaporate to obtain a crude product, then add toluene and sodium hydroxide solution, react at 80-90°C for 2-3h, and post-treat to obtain intermediate 1; S2: Under nitrogen protection, add toluene, high hydrogen silicone oil and intermediate 1 into the reactor, stir, heat to 70-110°C, slowly drop chloroplatinic acid-triphenylphosphine complex, react for 2-6 hours, and post-treat to obtain intermediate 2; S3: Under nitrogen protection, add toluene, intermediate 2, and thermoplastic phenolic resin into the reactor, stir, heat to 100-120°C, add triphenylphosphine and react for 6-8h, then cure at 150°C for 2h to obtain modified epoxy resin.

2. The sealing material for EBGA packaging according to claim 1, characterized in that: In the step S1, the mass ratio of 2,2'-diallylbisphenol A, epichlorohydrin and tetramethylammonium bromide is (5-8):(50-80):(0.1-0.3).

3. The sealing material for EBGA packaging according to claim 1, characterized in that: In the step S2, the mass ratio of toluene, high hydrogen-containing silicone oil, intermediate 1 and chloroplatinic acid-triphenylphosphine complex is 30:(8-10):(5-7):(0.1-0.3).

4. The sealing material for EBGA packaging according to claim 1, characterized in that: In the step S3, the mass ratio of toluene, intermediate 2, thermoplastic phenolic resin and triphenylphosphine is 20:(3-7):(1-9):(0.1-0.3).

5. The sealing material for EBGA packaging according to claim 1, characterized in that: The curing agent is a combination of one or more of methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride and pyromellitic anhydride.

6. The sealing material for EBGA packaging according to claim 1, characterized in that: The curing accelerator is one of N,N-dimethylethanolamine, bisphenol A and resorcinol.

7. The sealing material for EBGA packaging according to claim 1, characterized in that: The flame retardant is one of tributyl phosphate, tri(2-ethylhexyl) phosphate, and tri(2-chloroethyl) phosphate.

8. The sealing material for EBGA packaging according to claim 1, characterized in that: The inorganic filler is one or a combination of mica powder, calcium carbonate and barium sulfate.

9. A method for preparing a sealing material for EBGA packaging according to any one of claims 1 to 8, characterized in that: The following steps are involved: (1) Weigh by weight: modified epoxy resin: 80-100 parts, bismaleimide resin: 30-40 parts, curing agent: 8-10 parts, curing accelerator: 0.1-0.5 parts, flame retardant: 1-3 parts, inorganic filler: 10-20 parts; (2) The above raw materials are pre-mixed according to the mass ratio, and after being mixed evenly, the materials are melted, extruded and mixed, tableted and cooled, and then sheared and crushed by a high-speed mixer, and finally sieved to obtain the sealing material.

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