A low dielectric chip mount adhesive film composition, adhesive film

Abstract

The application provides a low-dielectric chip mounting adhesive film composition and adhesive film, which comprises the following raw materials by weight: 100 parts of epoxy resin, 10-30 parts of toughening agent, 40-50 parts of curing agent, 0.5-2 parts of accelerator, 100-250 parts of inorganic filler, the curing agent is compounded by an aryl difunctional primary amine curing agent and a trifunctional phenolic curing agent at a mass ratio of 3:10-12, the trifunctional phenolic curing agent is synthesized by Schiff base reaction with benzene triformyl derivative and amino phenol derivative as raw materials, the branched chain contains an aromatic ring structure and a C=N bond, and is a star-shaped three-arm compound, namely a trifunctional phenolic curing agent; due to the large volume of the aromatic ring structure and the strong rigidity of the C=N bond, the displacement space of the curing agent is small, the hindering ability of the polar group in the molecule is large, the polarization orientation can be better hindered, the molecular polarity after the curing of the adhesive film composition is reduced, and the dielectric constant and dielectric loss are reduced.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of semiconductor packaging, and particularly relates to a low-dielectric chip mounting adhesive film composition and an adhesive film. BACKGROUND

[0002] In a conventional semiconductor packaging process, glue such as epoxy resin and silica gel is often used in the chip mounting process. However, as the packaging size becomes smaller and the number of chips in a single package increases, the glue cannot meet the process requirements. The mounting adhesive film is a thin film composite material, which is attached to the back of the chip, thereby eliminating the glue drawing and dispensing process, greatly shortening the chip mounting process time, and thus improving the chip mounting process capacity.

[0003] Epoxy resin has excellent characteristics such as easy processing, chemical corrosion resistance, high mass fraction filling of fillers, and intrinsic insulation of resin. The mounting adhesive film with epoxy resin as the adhesive film base resin has a wide application in the field of semiconductor packaging. For example, a halogen-free epoxy resin flame-retardant adhesive and its adhesive film disclosed in patent CN101602925B include: 100 parts of epoxy resin, 35-50 parts of carboxyl-containing nitrile rubber, 8-15 parts of curing agent, and 0.5-2.0 parts of curing accelerator. The composition, adhesive film and chip packaging structure disclosed in patent CN114292615B include epoxy resin, interfacial active agent, curing agent and filler, and the interfacial active agent is selected from modified hexafluoropropylene compounds. The interfacial active agent in the composition is a modified hexafluoropropylene compound.

[0004] As can be seen from the above technology, the mounting adhesive film with epoxy resin as the adhesive film base resin can form a good mechanical fixing, electrical isolation, impact resistance, and thermal protection characteristic packaging layer for the chip. However, with the development of the microelectronics industry and the advent of the 5G era, the circuit integration is becoming higher and higher, and a series of problems such as signal transmission delay and crosstalk, dielectric loss leading to increased power consumption, and noise interference have occurred. The dielectric constant of the mounting adhesive film with epoxy resin as the adhesive film base resin cannot meet the requirements of the rapidly developing microelectronics industry, and it is necessary to further improve the adhesive film with epoxy resin as the base resin to reduce the overall dielectric constant of the adhesive film and further reduce the signal delay time. SUMMARY

[0005] To solve the above technical problems, the application provides a low dielectric chip mounting adhesive film composition and an adhesive film, a branched star-shaped three-arm compound with an aromatic ring structure and a C=N bond, i.e., a trifunctional phenolic curing agent, is synthesized by Schiff base reaction with benzene tricarboxaldehyde derivatives and amino phenol derivatives as raw materials.

[0006] To achieve the above object, the application adopts the following technical scheme:

[0007] The low dielectric chip mounting adhesive film composition comprises the following raw materials by weight: 100 parts of epoxy resin, 10-30 parts of toughening agent, 40-50 parts of curing agent, 0.5-2 parts of accelerator, and 100-250 parts of inorganic filler, wherein the curing agent is compounded by an aryl difunctional primary amine curing agent and a trifunctional phenolic curing agent at a mass ratio of 3:10-12, and the trifunctional phenolic curing agent has the following formula I:

[0008] Formula I:

[0009] wherein R1 is independently R2, R3 and R4 are independently a chemical bond or C1-C3 alkylene.

[0010] The aryl difunctional primary amine curing agent is selected from one or two or more combinations of 4,4'-diaminodiphenyl methane, 4,4'-diamino diphenyl ether, m-phenylenediamine, 3,4'-diaminodiphenyl methane and m-xylene diamine, and is preferably 4,4'-diaminodiphenyl methane. The compound of the aryl difunctional primary amine curing agent and the trifunctional phenolic curing agent is used as the curing agent, and the dielectric constant of the adhesive film can be obviously reduced by increasing the volume and rigidity of the curing agent. However, the compounding ratio needs to be appropriate: if the compounding ratio is too small, internal stress is easily generated in the adhesive film, which is easily released in a humid and hot environment, resulting in a decrease in the mechanical properties of the cured product of the adhesive film composition; and if the compounding ratio is too large, the space steric hindrance of the groups is insufficient to limit the movement of the molecular chain, and the effect of reducing the dielectric constant and dielectric loss of the epoxy resin is not obvious.

[0011] The trifunctional phenolic curing agent is prepared by Schiff base reaction of an aldehyde group on the benzene tricarboxaldehyde derivative and an amino group on the amino phenol derivative, and the molar ratio of the aldehyde group to the amino group is 0.9:1.12-1.18.

[0012] The benzene tricarboxaldehyde derivative is selected from one or a combination of two or more of benzene-1, 2, 4-tricarboxaldehyde, 3, 4', 5-tricarboxaldehyde-1, 1-biphenyl, [1, 1'-biphenyl]-3, 3', 5-tricarboxaldehyde, [1, 1': 3', 1"-terphenyl]-4, 4", 5'-tricarboxaldehyde, preferably [1, 1': 3', 1"-terphenyl]-4, 4", 5'-tricarboxaldehyde.

[0013] The amino phenol derivative is selected from one or a combination of two or more of p-aminophenol, m-aminophenol, o-aminophenol, 4-(aminomethyl)phenol, 3-(aminomethyl)phenol, 2-(aminomethyl)phenol, 2-(2-aminoethyl)phenol, 3-(2-aminoethyl)phenol, 4-hydroxyphenethylamine, 4-(3-aminopropyl)phenol, 2-(3-aminopropyl)phenol, 3-(3-amino-propyl)-phenol, preferably p-aminophenol.

[0014] Specifically, the trifunctional phenolic curing agent is prepared by a method comprising the following steps:

[0015] The benzene tricarboxaldehyde derivative, the amino phenol derivative, and the catalyst are dissolved in the organic solvent under an inert gas atmosphere, and the mixture is heated to reflux for 3-5 hours. After the reaction is completed, the mixture is naturally cooled to room temperature, and the solvent is removed by distillation under reduced pressure. The product is washed and recrystallized in ethanol to obtain the trifunctional phenolic curing agent.

[0016] The organic solvent comprises one or a combination of two or more of DMSO and DMF. The washing is performed 1-3 times with at least one of acetone, methyl ethyl ketone, n-butanol, and tetrahydrofuran. The recrystallization is performed in ethanol. The amount of the catalyst is 5-8 wt% of the total mass of the benzene tricarboxaldehyde derivative and the amino phenol derivative. The reaction time is 3-5 hours.

[0017] The epoxy resin is a mixed epoxy resin of a liquid bisphenol-type epoxy resin and a phenol biphenyl-type epoxy resin at a mass ratio of 1:3-4.

[0018] The liquid bisphenol-type epoxy resin has an epoxy equivalent weight of 170-250 g / eq, and the phenol biphenyl-type epoxy resin has an epoxy equivalent weight of 200-300 g / eq.

[0019] The toughening agent is selected from one or a combination of two or more of nitrile rubber, nitrile rubber derivative, natural rubber, and ethylene-propylene rubber. Preferably, the toughening agent is nitrile rubber derivative, and more preferably, the toughening agent is liquid nitrile rubber modified by epoxy with an epoxy equivalent weight of 1200-1800 g / eq.

[0020] The curing accelerator is selected from one or a combination of two of an organic amine, an imidazole compound; the organic amine is selected from one or a combination of two or more of triethylamine, benzyldimethylamine, pyridine; the imidazole compound is selected from one or a combination of two or more of imidazole, 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dimethylolimidazole and 2-phenyl-4-methyl-5-methylolimidazole.

[0021] The average particle size of the inorganic filler is 0.1-3 μm, preferably 0.5-1.5, and is selected from one or a combination of two or more of silicon dioxide, calcium carbonate, aluminum hydroxide, magnesium hydroxide, aluminum oxide, aluminum nitride, silicon nitride, boron nitride, and is preferably silicon dioxide.

[0022] The low dielectric chip mounting adhesive film composition further comprises an organic solvent selected from one or a combination of two or more of toluene, xylene, butanone, acetone, methyl ethyl ketone, cyclohexanone, ethyl acetate, N,N-dimethylformamide.

[0023] The mass fraction of the organic solvent in the low dielectric chip mounting adhesive film composition is 40-60 wt%.

[0024] An adhesive film is obtained by coating the low dielectric chip mounting adhesive film composition on a release film.

[0025] Specifically, the preparation method of the adhesive film comprises the following steps: uniformly mixing epoxy resin, toughening agent, curing agent, curing accelerator, inorganic filler and organic solvent, coating on a release film, and drying to obtain.

[0026] The thickness of the release film is 20-60 μm, and is selected from one or a combination of two or more of PET film, polyethylene film, polypropylene film, and polyvinyl chloride film; the thickness of the low dielectric chip mounting adhesive film composition after drying is 5-50 μm, and is preferably 10-30 μm.

[0027] The drying temperature is 80-130 °C, and the drying time is 3-15 min.

[0028] The curing condition of the adhesive film is 150-170 °C for 1-3 h.

[0029] Compared with the prior art, the present application has the following beneficial effects:

[0030] The present application uses benzene tricarboxaldehyde derivative and aminophenol derivative as raw materials to synthesize a branched star-shaped three-arm compound with aromatic ring structure and C=N bond, i.e. trifunctional phenolic curing agent, due to the larger volume of the aromatic ring structure and the stronger rigidity of the C=N bond, the displacement space of the curing agent is smaller, the hindering ability of the polar group in the molecule is larger, the polarization orientation can be better hindered, the molecular polarity after the curing of the film composition is reduced, and the dielectric constant and dielectric loss are reduced. DETAILED DESCRIPTION

[0031] The present application will be further described below in combination with specific examples, but is not limited to the contents of the specification. Unless otherwise specified, the "parts" in the examples of the present application are all weight parts. The reagents used are all commercially available reagents in the art.

[0032] The epoxy-modified butyronitrile liquid rubber is purchased from Huntsman Corporation, with the trade name of Baysilon®RK84L. RK84L, which is an epoxy-modified butyronitrile liquid rubber, with a butyronitrile rubber content of 32% and an epoxy equivalent weight of 1250-1500 g / eq.

[0033] The PET release film is purchased from Zhejiang Jimei Electronic Technology Co., Ltd., with a thickness of 50 μm.

[0034] The liquid bisphenol A type epoxy resin is purchased from Dow Chemical, with the trade name of DER 331-EL, and an epoxy equivalent weight of 190 g / eq.

[0035] The phenol biphenyl type epoxy resin is purchased from Shandong Shengquan Chemical Co., Ltd., with the trade name of SQXN-324, and an epoxy equivalent weight of 300 g / eq.

[0036] The spherical silica is purchased from Japan Yatomar Co., Ltd., with the trade name of SO-C4, a specific surface area of 3-6 m 2 / g, and an average particle size of 0.9 μm.

[0037] Example 1

[0038] 1) Under a nitrogen atmosphere, 0.3 mol of [1,1':3',1"-terphenyl]-4,4",5'-tricarboxaldehyde and 1.18 mol of p-aminophenol were dissolved in 500 mL of DMF, 12 g of glacial acetic acid was added as a catalyst, and the reaction was carried out at reflux for 5 h. After the reaction was completed, the mixture was naturally cooled to room temperature, the mixed solvent was removed by distillation under reduced pressure, the solid was washed with acetone for 3 times, and recrystallization in ethanol was performed to obtain the trifunctional phenolic curing agent. The reaction formula of this step is shown below;

[0039]

[0040] 2) 20 g of liquid bisphenol A type epoxy resin DER 331-EL, 80 g of SQXN-324, and 30 g of butyronitrile rubber derivative RK84L, 50 g curing agent compounded by 4,4'-diaminodiphenylmethane and the trifunctional phenolic curing agent obtained in step 1) at a mass ratio of 3:10, 1 g 2-methylimidazole, 150 g spherical silica SQ-5, 235 g acetone were uniformly mixed to obtain a low dielectric chip mounting adhesive film composition. The adhesive film composition was coated on a PET release film, dried at 80°C for 10 min, and the thickness of the adhesive film composition after drying was 25 μm to obtain an adhesive film.

[0041] Example 2

[0042] The rest was the same as example 1, except that in step 2), the mass ratio of 4,4'-diaminodiphenylmethane to trifunctional phenolic curing agent was 3:12.

[0043] Example 3

[0044] The rest was the same as example 1, except that the amount of p-aminophenol used in step 1) was 1.12 mol.

[0045] Example 4

[0046] The rest was the same as example 1, except that equimolar amount of 4-(aminomethyl)phenol was used instead of aminophenol.

[0047] Example 5

[0048] The rest was the same as example 1, except that equimolar amount of trimesic aldehyde was used instead of [1,1':3',1"-terphenyl]-4,4",5'-tricarboxaldehyde.

[0049] Example 6

[0050] The rest was the same as example 1, except that the amount of curing agent was 40 g.

[0051] Example 7

[0052] The rest was the same as example 1, except that in step 2), 25 g of liquid bisphenol A type epoxy resin DER 331-EL, 75 g of spring SQXN-324, 10 g of butyl nitrile rubber derivative RK84L, 50 g curing agent compounded by 4,4'-diaminodiphenylmethane and the trifunctional phenolic curing agent obtained in step 1) at a mass ratio of 3:12, 1 g 2-methylimidazole, 150 g spherical silica SQ-5, 235 g acetone were uniformly mixed to obtain a low dielectric chip mounting adhesive film composition. The adhesive film composition was coated on a PET release film, dried at 80°C for 10 min, and the thickness of the adhesive film composition after drying was 25 μm to obtain an adhesive film.

[0053] Comparative Example 1

[0054] The rest is the same as example 1, except that the curing agent in step 2) is compounded by 4,4'-diaminodiphenyl methane and the tri-functional phenolic curing agent obtained in step 1) at a mass ratio of 1:12.

[0055] Comparative example 2

[0056] The rest is the same as example 1, except that the curing agent in step 2) is compounded by 4,4'-diaminodiphenyl methane and the tri-functional phenolic curing agent obtained in step 1) at a mass ratio of 5:12.

[0057] The adhesive film prepared in the above examples and comparative examples is cured at 170℃ for 2h, and then the following performance tests are carried out:

[0058] Shear strength: The wafer with a thickness of 25μm is cut into a size of 50mm×50mm, then the adhesive film is pasted to the mirror surface of the wafer at 70℃, and then the PET release film is removed, the wafer adhesive film is bonded to the copper substrate at 120℃, 0.2kg, 1s, and finally the sample is heated and cured at 170℃ for 2h. The full-automatic push-pull force testing machine WBE-9088B of Dongguan Weibang Instrument and Equipment Co., Ltd. is used to test the shear strength at a speed of 0.2mm / s.

[0059] Hygrothermal aging: aging at 85℃, humidity of 85%RH for 168h, retesting the above shear strength, and calculating the shear strength loss rate.

[0060] Dielectric properties: including dielectric coefficient (Dk) and dielectric loss tangent (Df) tests, the sample is cut into a square piece of 50mm×50mm×25μm, and after drying, the dielectric properties are tested at room temperature using an E4991A RF impedance tester from Agilent at a test frequency of 1GHz.

[0061] Table 1 test results

[0062] Item Dk Df Shear strength MPa Loss rate of shear strength after hygrothermal aging % Example 1 3.0 0.020 7.2 1.5 Example 2 2.8 0.026 7.4 1.8 Example 3 3.0 0.021 7.1 1.5 Example 4 3.1 0.029 7.0 2.0 Example 5 3.3 0.027 6.6 2.9 Example 6 3.4 0.030 6.4 2.1 Example 7 3.2 0.028 6.9 2.2 Comparative Example 1 2.8 0.014 7.5 8.7 Comparative Example 2 3.7 0.130 6.1 3.8

[0063] As can be seen from Table 1, the adhesive film prepared in the present application has lower dielectric constant, dielectric loss, and higher shear strength, which can better protect the chip from external mechanical stress damage, thereby improving the reliability and service life of the chip.

[0064] The above detailed description is a specific description of one of the feasible embodiments of the present application, which is not used to limit the patent scope of the present application, and any equivalent implementation or change without departing from the present application shall be included in the scope of the technical solutions of the present application.

Claims

1. A low dielectric chip mount adhesive film composition, characterized by, The raw materials include 100 parts of epoxy resin, 10-30 parts of toughening agent, 40-50 parts of curing agent, 0-2 parts of accelerator, 100-250 parts of inorganic filler, the curing agent is compounded by aryl difunctional primary amine curing agent and trifunctional phenolic curing agent with a mass ratio of 3:10-12, the trifunctional phenolic curing agent has the following formula I: Formula I: ; wherein R1is independently , , , , ; R2, R3, R4are independently a chemical bond, C1-C3 alkylene.

2. The low dielectric chip mount adhesive film composition according to claim 1, wherein, The aryl difunctional primary amine curing agent is selected from one or more than two combinations of 4,4'-diaminodiphenyl methane, 4,4'-diamino diphenyl ether, m-phenylenediamine, 3,4'-diaminodiphenyl methane, m-xylene diamine.

3. The low dielectric chip on film adhesive composition of claim 2, wherein, The aryl difunctional primary amine curing agent is 4,4'-diaminodiphenyl methane.

4. The low dielectric chip on film adhesive composition of claim 1, wherein, The trifunctional phenolic curing agent is prepared by Schiff base reaction of aldehyde group on benzene triformaldehyde derivative and amino group on aminophenol derivative, the molar ratio of aldehyde group to amino group is 0.9:1.12-1.18; the benzene triformaldehyde derivative is selected from one or more than two combinations of triformophenol, benzene-1,2,4-tricarboxaldehyde, 3,4',5-tricarboxaldehyde-1,1-biphenyl, [1,1'-biphenyl]-3,3',5-tricarboxaldehyde, [1,1':3',1''-terphenyl]-4,4'',5'-tricarboxaldehyde; the aminophenol derivative is selected from one or more than two combinations of p-aminophenol, m-aminophenol, o-aminophenol, 4-(aminomethyl)phenol, 3-(aminomethyl)phenol, 2-(aminomethyl)phenol, 2-(2-aminoethyl)phenol, 3-(2-aminoethyl)phenol, 4-hydroxyphenethylamine, 4-(3-aminopropyl)phenol, 2-(3-aminopropyl)phenol, 3-(3-amino-propyl)-phenol.

5. The low dielectric chip on film adhesive composition of claim 4, wherein, The benzene triformaldehyde derivative is [1,1':3',1''-terphenyl]-4,4'',5'-tricarboxaldehyde.

6. The low dielectric chip on film adhesive composition of claim 4, wherein, The aminophenol derivative is p-aminophenol.

7. The low dielectric chip on film adhesive composition of claim 4, wherein, The trifunctional phenolic curing agent is prepared by the method comprising the following steps: Under the inert gas atmosphere, the benzene triformaldehyde derivative and the aminophenol derivative are dissolved in the organic solvent, the glacial acetic acid catalyst is added, the temperature is raised to the reflux state for reaction, after the reaction is completed, the temperature is naturally cooled to room temperature, the solvent is removed by reduced pressure distillation, washed, and recrystallized to obtain the trifunctional phenolic curing agent.

8. The low dielectric chip on film adhesive composition of claim 7, wherein, The organic solvent includes one or a combination of DMSO and DMF; the recrystallization is recrystallization in ethanol; the amount of the glacial acetic acid catalyst is 5-8wt% of the mass sum of the benzene triformaldehyde derivative and the aminophenol derivative; the reaction time is 3-5h.

9. The low dielectric chip on film adhesive composition of claim 1, wherein, The epoxy resin is a mixed epoxy resin with a mass ratio of 1:3-4 of liquid bisphenol type epoxy resin and phenol biphenyl type epoxy resin; the epoxy equivalent weight of the liquid bisphenol type epoxy resin is 170-250g / eq, and the epoxy equivalent weight of the phenol biphenyl type epoxy resin is 200-300g / eq.

10. The low dielectric chip on film adhesive composition of claim 1, wherein, The low dielectric chip mounting adhesive film composition further comprises an organic solvent selected from one or more than two combinations of toluene, xylene, butanone, acetone, methyl ethyl ketone, cyclohexanone, ethyl acetate, N,N-dimethylformamide; the mass fraction of the organic solvent in the low dielectric chip mounting adhesive film composition is 40-60 wt%.

11. An adhesive film obtained by coating the low dielectric chip mounting adhesive film composition according to any one of claims 1-10 on a release film.

12. The film of claim 11, wherein, The preparation method of the adhesive film comprises the following steps: uniformly mixing the epoxy resin, the toughening agent, the curing agent, the accelerator, the inorganic filler and the organic solvent, coating on a release film, drying, and obtaining.

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