An insulating adhesive composition containing BMI and its application

Abstract

The present invention provides an insulating adhesive composition containing BMI and its application. The composition is obtained by dissolving BMI resin in a solvent, then mixing it with cyanate ester resin, adding auxiliaries such as a first curing accelerator, a second curing accelerator, and silica powder filler, and fully dispersing them evenly. The composition can achieve high room temperature / high temperature bonding strength, with a high temperature thrust at 300°C exceeding 2 kg (>5 MPa) and good resistance to damp heat.

Description

Technical Field

[0001] The present invention belongs to the technical field of chip mounting, and particularly relates to an insulating adhesive composition containing BMI and its application. Background Art

[0002] In the preparation and assembly of semiconductor packages and microelectronic devices, adhesives play many functions, including: bonding, fixing, sealing and protecting, gap filling, grounding, insulation, flame retardancy, etc. The most common use is to mount electronic components or integrated circuit chips on lead frames or plastic substrates. After the adhesive is cured by heat baking (Baking), and then through processes such as wire bonding and encapsulation with epoxy molding compound (EMC), the packaged device becomes a part of the printed circuit board or an important electrical component after high-temperature reflow soldering (Reflow).

[0003] Adhesives for electronic packaging usually need to meet process performance and service performance for convenient application. Process performance includes: having appropriate rheological properties to cope with construction methods in various application scenarios; the curing temperature of the adhesive cannot be too high or the time too long; service performance requires that the adhesive has good mechanical strength and low moisture absorption rate after curing, can withstand the high temperature of multiple reflow soldering processes, and has an appropriate coefficient of thermal expansion (CTE) relative to substrates, molding compounds, etc.

[0004] Currently, the mainstream adhesives for chip mounting are curing systems based on epoxy resin as the matrix resin. With the improvement of chip integration, heat generation and dissipation have become problems that cannot be ignored. Especially with the popular application of power semiconductors, high requirements are put forward for the heat resistance and moisture resistance of adhesives. Traditional chip adhesives based on epoxy resin systems can no longer meet the increasingly demanding application requirements. Summary of the Invention

[0005] The first object of the present invention is to provide an insulating adhesive composition containing BMI.

[0006] To achieve the above object, the following technical solutions are adopted in the present invention:

[0007] An insulating adhesive composition containing BMI, comprising: BMI resin, organic solvent, cyanate resin, first curing accelerator, second curing accelerator, and silicon powder;

[0008] Wherein: in parts by weight,

[0009] the BMI resin is a parts,

[0010] the cyanate resin is b parts,

[0011] c parts of a first curing accelerator, the first curing accelerator being an organometallic compound, which is used to accelerate the curing reaction rate of the BMI resin and the cyanate resin; the first curing accelerator can be used alone or in combination of two or more, and its addition amount ranges from 10 to 500 ppm relative to the addition amount of the cyanate resin, preferably 25 to 200 ppm;

[0012] d parts of a second curing accelerator, the second curing accelerator being a primary phenolic compound, which is used to react with unreacted cyanate groups to form imide carbonate to reduce the dielectric constant and loss factor;

[0013] e parts of silica powder;

[0014] The weight ratio of the cyanate resin to the BMI resin is b / a = 2 to 4;

[0015] The weight ratio of the second curing accelerator to the BMI resin is d / a = 0.1 to 0.2;

[0016] The weight ratio of the silica powder to the total weight of the BMI resin, organic solvent, cyanate resin, first curing accelerator, and second curing accelerator is 1 to 2.

[0017] While adopting the above technical solutions, the present invention can also adopt or combine the following technical solutions:

[0018] As a preferred technical solution of the present invention: the monomers of the BMI resin are selected from at least one of N,N'-m-phenylene bismaleimide, 4,4'-diphenylmethane bismaleimide, N,N'-(2,2'-diethyl-6,6'-methylenediphenyl) bismaleimide, 2,2'-bis[4-(4'-maleimidooxy)phenyl]propane, N,N'-(4-methyl-m-phenylene) bismaleimide, N,N'-m-phenylene bismaleimide, polyphenylmethane bismaleimide, bisphenol A diphenyl ether bismaleimide, 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethane bismaleimide, 4-methyl-1,3-phenylene bismaleimide, 1,6-bismaleimide(2,2,4-trimethyl)hexane or the BMI resin is a 4,4'-methylenedianiline-based diphenylmethane-4,4'-bismaleimide polymer.

[0019] As a preferred technical solution of the present invention: the BMI resin is selected from at least one of SR525 (the monomer is N,N'-m-phenylene bismaleimide) of Sartomer Company, Homide121 (the monomer is 4,4'-diphenylmethane bismaleimide) of HOS-TechnikGmbh Company, Matrimide5292A of Huntsman Company, N,N'-(4-methyl-m-phenylene) bismaleimide, N,N'-m-phenylene bismaleimide, polyphenylmethane bismaleimide, N-phenylmaleimide, 2,6-dimethylphenylmaleimide, N-cyclohexylmaleimide, Homide250 bismaleimide resin and Homide400 bismaleimide resin of HOS-TechnikGmbh (Australia) Company, BMI-1000, 1000H, 1100, 1100H, 4000, 5100, 7000, 7000H, TMH of Daiwakasei Industry Co., Ltd (Japan).

[0020] As a preferred technical solution of the present invention: the organic solvent is at least one of N,N'-dimethylformamide (DMF), N-methyl-2-pyrrolidone (NMP), N,N'-dimethylacetamide, N-ethyl-2-pyrrolidone, dimethyl sulfoxide, toluene, xylene, methyl ethyl ketone, acetone, butanone, dichloromethane, dichloroethane, chloroform, tetrahydrofuran, methyltetrahydrofuran, ethylene glycol dimethyl ether, ethylene glycol monoethyl ether, ethylene glycol diethyl ether.

[0021] As a preferred technical solution of the present invention: the monomer of the cyanate ester resin is selected from at least one of bisphenol A cyanate ester, bisphenol B cyanate ester, bisphenol E cyanate ester, bisphenol F cyanate ester, bisphenol M cyanate ester, bisphenol AF cyanate ester, bisphenol AP cyanate ester, bisphenol BP cyanate ester, phenolic cyanate ester, dicyclopentadiene-based cyanate ester;

[0022] The molecular structure of the monomer of the cyanate ester resin contains a diphenol derivative with 2 or more cyanate ester groups (O-C≡N-), and it can undergo a cyclotrimerization reaction when heated to form a three-dimensional network with a high crosslinking density of triazine rings.

[0023] As a preferred technical solution of the present invention: the cyanate ester resin is selected from at least one of L-10, M-10, B-10 of Ciba Geigy Company; Primaset PT30, PT30 S75, PT60, PT60S of LONZA Company, and L-10 cyanate ester resin of Hubei Jiahui Xingcheng Biotechnology Co., Ltd.

[0024] As a preferred technical solution of the present invention: the first curing accelerator is selected from at least one of organic copper compounds, organic zinc compounds, and organic cobalt compounds;

[0025] The organic copper compound is preferably copper (II) acetylacetonate;

[0026] The organic zinc compound is preferably zinc (II) acetylacetonate;

[0027] The organic cobalt compound is preferably cobalt (II) acetylacetonate and cobalt (III) acetylacetonate.

[0028] As a preferred technical solution of the present invention: the second curing accelerator is selected from at least one of nonylphenol, dinonylphenol, octylphenol, and 4-cumylphenol.

[0029] As a preferred technical solution of the present invention: the silica powder is spherical silica powder, and the average particle size of the spherical silica powder is 0.5 - 10 μm, and the average particle size is preferably 0.5 - 5 μm;

[0030] The silica powder is selected from at least one of Admatech FE920A, SC6200-STE, SO-C5, and SC220G.

[0031] Another object of the present invention is to provide an application of the BMI-containing insulating adhesive composition described above in chip mounting.

[0032] It should be noted that in the art, resins include small molecule monomers, small molecule polymers, macromolecule polymers, etc.

[0033] The present invention provides a BMI-containing insulating adhesive composition and its application. Using BMI resin, after being dissolved in a solvent and combined with cyanate resin, adding auxiliaries such as the first curing accelerator, the second curing accelerator, and silica powder filler, the obtained composition after being fully dispersed and homogenized can achieve high room temperature / high temperature bonding strength, the high temperature thrust at 300 °C exceeds 2 kg (>5 MPa), and it has good moisture and heat resistance. Detailed Description of the Invention

[0034] The present invention will be further described in detail with reference to specific examples.

[0035] 1. Test Preparation

[0036] 1.1 Test Materials

[0037]

[0038] 1.2 Performance Testing

[0039] Volume resistivity test: Refer to the national standard "GB / T 1410 - 2006",

[0040] Sample size: A disc with a diameter of 8 cm and a thickness of 2 mm;

[0041] Testing equipment: ZC36 type high insulation resistance measuring instrument (Shanghai Precision Instrument and Meter Co., Ltd.).

[0042] Adhesive strength test: The test method refers to "HG / T 5912-2021 Conductive Adhesive",

[0043] The size of the silicon wafer is: 2 mm × 2 mm; the substrate is a silver-plated copper sheet, and the curing condition is a hot stage at 175 °C for 60 min; the testing equipment is a DAGE-4000P multi-functional push-pull force machine (Nordson DAGE Precision Industries LTD, USA), with a temperature-controlled heating stage, and the shear strength is the magnitude of the pushing force (unit: kgF, kilogram-force); 5 specimens are taken for each adhesive sample, and the arithmetic mean is taken. When measuring the high-temperature pushing force, set the temperature of the temperature-controlled heating stage, wait for 5 min after reaching the target temperature and then start measuring the pushing force.

[0044] Evaluation of the residual glue rate on the failure surface: Observe the residual glue on the substrate after the pushing force failure through an optical microscope, and evaluate the area ratio (percentage relative to the chip area) of the part with residual glue. A 10-point system is adopted, with 100% residual glue corresponding to 10; 90% residual glue corresponding to 9, and so on, 10% residual glue corresponding to 1; 0% residual glue corresponding to 0; the arithmetic mean is taken for 10 samples.

[0045] Water absorption test: Refer to the national standard "GB / T35494.1-2017",

[0046] Sample size: 2 cm × 1 cm × 50 - 100 μm (thickness); the specimen is placed in an oven at 105 °C - 120 °C and dried for 1 h - 4 h, taken out and weighed as the initial mass; 5 samples are in a group;

[0047] After curing for 168 h under the double 85 conditions (constant temperature and humidity box, 85% relative humidity and 85 °C), it is cooled to room temperature and weighed, and the water absorption rate of water vapor is calculated according to the mass change.

[0048] 2. Test procedure

[0049] 2.1 Preparation of insulating glue (taking Example 1 as an example)

[0050] Weigh 3 portions of BMI resin and add them to a mixing kettle. Then add 10 parts of NMP and dissolve while stirring until it becomes completely clear. Add 8 parts of cyanate resin L10, 0.02 part of copper acetylacetonate, and 0.4 part of nonylphenol, and mix at 800 rpm for 15 min. Finally, add 1 times the amount of silica FE920A (1 times the amount), disperse at 800 rpm for 15 min, and then perform vacuum degassing for 10 min with a vacuum degree < -0.095 MPa. Discharge under normal pressure to obtain an insulating adhesive sample.

[0051] Table 1

[0052]

[0053]

[0054] Table 2

[0055]

[0056] 3. Results and Discussion:

[0057] In Examples 1 / 2 / 3 / 6, NMP is used as the dispersion solvent for BMI resin. In Examples 1 / 2 / 3, with the same content of BMI resin, the amount of cyanate resin increases from 8 parts to 12 parts. In terms of performance, the room temperature thrust increases from 4.8 kgF to 6.6 kgF, while for the high temperature thrust, the thrust first increases and then decreases, that is, it increases from 3.4 kgF to 4.1 kgF and then decreases to 2.5 kgF; the high temperature residual glue rate continuously decreases, from 7 to 4. Relatively speaking, the moisture absorption rate of Example 2 is the lowest, reaching 0.25%.

[0058] In Examples 4 / 5, DMF is used as the dispersion solvent for BMI resin. Compared with Example 1 using NMP as the solvent, under the same other conditions, the normal temperature chip thrust (3.4 kgF) and high temperature chip thrust (2.2 kgF) of Example 4 both decrease; another obvious phenomenon is that the moisture absorption rate and the high temperature damage surface are both improved to a certain extent. Similarly, there is also Example 5 compared with Example 3.

[0059] The main difference between Example 6 and Example 2 is that the amount of silica powder filler is increased from 1 times to 2 times. The results are that both the normal temperature chip thrust and the high temperature chip thrust decrease, from 6.2 kgF to 4.3 kgF and from 4.1 kgF to 3.2 kgF respectively; the residual glue rate basically changes little, but the moisture absorption rate is improved, from 0.25% to 0.22%.

[0060] Comparative Example 1 compared with Examples 1-3, is that the cyanate resin was not added, and the results are as follows: the chip thrust at room temperature decreased to less than 2 kgF (1.5 kgF), and the chip thrust at high temperature was only 0.2 kgF; the residual glue rate was only 2, while the moisture absorption rate reached 0.8%.

[0061] Comparative Example 2 compared with Example 1, nonylphenol was not added, and the results are as follows: both the chip thrust at room temperature and the chip thrust at high temperature decreased significantly, but the change in the residual glue surface and the moisture absorption rate was small.

[0062] Comparative Example 3 compared with Example 1, the amount of nonylphenol was increased from 0.4 to 1.0 parts, and the results are as follows: the chip thrust at room temperature, the chip thrust at high temperature, and the moisture absorption rate changed little, but the residual glue rate decreased from 7 to 3.

[0063] Comparative Example 4 compared with Example 1, the main difference is that the powder filler was changed from FE920A to SC6200-STE, and the particle size distributions of the two powders were different. The former was in the range of 5-25 μm, while the latter was in the range of 2-25 μm. The results of the change are as follows: the chip thrust at room temperature increased from 4.8 kgF to 5.6 kgF, but the chip thrust at high temperature decreased from 3.4 kgF to 2.4 kgF, and the change in the residual glue rate and the moisture absorption rate was small.

[0064] The above specific embodiments are used to explain and illustrate the present invention, and are only the preferred embodiments of the present invention, rather than limiting the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and scope of the claims of the present invention fall within the protection scope of the present invention.

Claims

1. An insulating adhesive composition containing BMI, characterized in that: The BMI-containing insulating adhesive composition comprises: BMI resin, organic solvent, cyanate resin, a first curing accelerator, a second curing accelerator and silicon powder; Wherein: by weight, BMI resin is a part, Cyanate resin is part b, c parts of a first curing accelerator, wherein the first curing accelerator is an organic metal compound; d parts of a second curing accelerator, wherein the second curing accelerator is a primary phenolic compound; Silica fume is e parts; The weight ratio of the cyanate resin to the BMI resin is b / a=2-4; The weight ratio of the second curing accelerator to the weight ratio of the BMI resin is d / a=0.1-0.2; The weight ratio of the silicon powder to the total weight of the BMI resin, the organic solvent, the cyanate resin, the first curing accelerator, and the second curing accelerator is 1 to 2; The silicon powder is silicon dioxide FE920A.

2. The insulating adhesive composition containing BMI according to claim 1, characterized in that: The monomers of the BMI resin are selected from N,N' -m-phenylene bismaleimide, 4,4'-diphenylmethane bismaleimide, N,N' -(2,2'-diethyl-6,6'-methylenediphenyl)bismaleimide, 2,2'-bis[4-(4'-maleimidooxy)phenyl]propane, N,N' -(4-methyl-m-phenylene)bismaleimide, N,N' The BMI resin is at least one of: -m-phenylene bismaleimide, polyphenylmethane bismaleimide, bisphenol A diphenyl ether bismaleimide, 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethane bismaleimide, 4-methyl-1,3-phenylene bismaleimide, 1,6-bismaleimide (2,2,4-trimethyl) hexane, or the BMI resin is a diphenylmethane-4,4'-bismaleimide polymer with 4,4'-methylenedianiline.

3. The insulating adhesive composition containing BMI according to claim 1, characterized in that: The organic solvent is N,N' -dimethylformamide, N -Methyl-2-pyrrolidone, N-N' -Dimethylacetamide, N -At least one of ethyl-2-pyrrolidone, dimethyl sulfoxide, toluene, xylene, methyl ethyl ketone, acetone, butanone, dichloromethane, dichloroethane, chloroform, tetrahydrofuran, methyltetrahydrofuran, ethylene glycol dimethyl ether, ethylene glycol monoethyl ether, and ethylene glycol diethyl ether.

4. The insulating adhesive composition containing BMI according to claim 1, characterized in that: The monomer of the cyanate resin is selected from at least one of bisphenol A cyanate, bisphenol B cyanate, bisphenol E cyanate, bisphenol F cyanate, bisphenol M cyanate, bisphenol AF cyanate, bisphenol AP cyanate, bisphenol BP cyanate, phenolic cyanate and dicyclopentadiene cyanate.

5. The insulating adhesive composition containing BMI according to claim 1, characterized in that: The first curing accelerator is selected from at least one of an organic copper compound, an organic zinc compound, and an organic cobalt compound; The organic copper compound is copper acetylacetonate II; The organic zinc compound is zinc acetylacetonate II; The organic cobalt compound is cobalt acetylacetonate II or cobalt acetylacetonate III.

6. The insulating adhesive composition containing BMI according to claim 1, characterized in that: The second curing accelerator is selected from at least one of nonylphenol, dinonylphenol, octylphenol and 4-cumylphenol.

7. Use of the BMI-containing insulating adhesive composition according to any one of claims 1 to 6 in chip mounting.

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