Epoxy molding compound and preparation method and application thereof

Abstract

The invention provides an epoxy molding compound as well as a preparation method and application thereof, and the epoxy molding compound is prepared from the following raw materials in parts by weight: 130-210 parts of modified spherical filler; 8-15 parts of epoxy resin; 8-18 parts of a curing agent; 0.05 to 0.2 part of an accelerant; the modified spherical filler is spherical alloy powder coated with silicon dioxide on the surface. According to the invention, the spherical alloy powder coated with silicon dioxide on the surface is used as a filler, and the epoxy resin is used as a base adhesive, so that the prepared epoxy molding compound has excellent electrical insulation property and electromagnetic shielding property, and also has high glass transition temperature and low thermal expansion coefficient; and the method has a wide application prospect in SiP structure-function integrated packaging.

Description

Technical Field

[0001] The invention belongs to the technical field of electronic industry, and relates to an epoxy molding compound and a preparation method and application thereof, and specifically relates to an epoxy molding compound with electrical insulation and electromagnetic shielding performance and a preparation method and application thereof. Background Art

[0002] The rapid progress of big data, artificial intelligence, cloud computing and 5G communication technology has put forward higher performance requirements for high-end chip manufacturing. In order to break through the physical manufacturing limits inherent in lithography technology and pursue higher integration and system integration capabilities, the industry has turned to advanced packaging technology as a key solution.

[0003] SiP packaging (System in a Package) is an advanced electronic device packaging technology that integrates multiple functional chips, including processors, memory and other functional chips, into one package based on application scenarios, the number of packaging substrate layers and other factors, thereby achieving a basically complete function. However, the multiple chips, circuit components and power modules integrated inside the SiP package will generate electromagnetic radiation when working. Without effective electromagnetic shielding measures, these radiations may interfere with each other, causing signal distortion, increased bit error rate and other problems, thereby affecting the stability and reliability of the entire system. Therefore, electromagnetic interference protection for SiP packaging is an indispensable part of the design and manufacturing process of electronic products.

[0004] The EMI protection of SiP packaging can solve the EMI problem between the inside of the package and the surrounding environment. It is a key measure to ensure system reliability, meet EMI requirements, cope with the trend of high integration and high-speed and high-frequency signal transmission, and achieve miniaturization design.

[0005] For electromagnetic protection of packaged chips, the traditional electromagnetic shielding method is to install a metal cover on the outside of the electronic components to wrap the electronic equipment or circuits to reduce or prevent the interference of the electromagnetic field on the internal circuit and the leakage of internal electromagnetic radiation to the outside. However, the shielding cover occupies valuable printed circuit board area in the horizontal and vertical directions, which poses a great obstacle to the miniaturization of the equipment.

[0006] The existing conformal shielding technology sprays, electroplates or sputters a layer of conductive material on the epoxy molding compound (EMC), which no longer requires an external shielding cover and does not take up additional equipment space. However, the manufacturing process of conformal shielding is relatively complicated. Each method has its own specific process flow and parameter requirements, which require precise control to ensure the quality and performance of the shielding layer. In addition, the complexity of the manufacturing process also leads to an increase in production costs.

[0007] In view of the high-integration electromagnetic complexity of SiP packaging and the thermal, mechanical and electrical challenges during operation, it is urgent to develop a new type of structural-functional integrated epoxy molding compound, which can give the epoxy molding compound electromagnetic shielding properties so that it not only has the electrical protection and mechanical support of epoxy molding compound, but also can resist electromagnetic interference to ensure the normal operation of the chip. Summary of the invention

[0008] In view of the deficiencies in the prior art, the object of the present invention is to provide an epoxy molding compound and a preparation method and application thereof, and specifically to provide an epoxy molding compound with electrical insulation and electromagnetic shielding performance and a preparation method and application thereof. The scheme adopted by the present invention adds the insulation modification process on the basis of the epoxy molding compound preparation process, which only requires simple physical and chemical methods, a short preparation process, low material cost, and can be produced on a large scale. The epoxy molding compound provided by the present invention is used for SiP packaging, which greatly simplifies the packaging procedure, and high integration and lightweight chip packaging can be achieved without the need for additional electromagnetic shielding materials and their process flow. The structural-functional integrated epoxy molding compound provided by the present invention will become a future hot spot and development trend in the field of EMC materials.

[0009] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0010] In a first aspect, the present invention provides an epoxy molding compound, wherein the raw materials for preparing the epoxy molding compound include the following components in parts by weight:

[0011]

[0012]

[0013] The modified spherical filler is a spherical alloy powder with silicon dioxide coated on the surface.

[0014] The present invention uses spherical alloy powder coated with silicon dioxide as filler and epoxy resin as base glue. The prepared epoxy molding compound has excellent electrical insulation performance and electromagnetic shielding performance, and also has high glass transition temperature (Tg) and low coefficient of thermal expansion (CTE). It has broad application prospects in the structural-functional integrated packaging of SiP.

[0015] In the present invention, the raw materials for preparing the epoxy molding compound are measured by weight, and the amount of the modified spherical filler can be 130 parts, 132 parts, 134 parts, 136 parts, 138 parts, 140 parts, 142 parts, 144 parts, 146 parts, 148 parts, 150 parts, 152 parts, 154 parts, 156 parts, 158 parts, 160 parts, 162 parts, 164 parts, 166 parts, 168 parts, 170 parts, 172 parts, 174 parts, 176 parts, 178 parts, 180 parts, 182 parts, 184 parts, 186 parts, 188 parts, 190 parts, 192 parts, 194 parts, 196 parts, 198 parts, 200 parts, 202 parts, 204 parts, 206 parts, 208 parts, 210 parts, etc.

[0016] In the present invention, the raw materials for preparing the epoxy molding compound are calculated by weight, and the amount of epoxy resin used can be 8 parts, 9 parts, 10 parts, 12 parts, 14 parts, 15 parts, etc.

[0017] In the present invention, the raw materials for preparing the epoxy molding compound are measured by weight, and the amount of the curing agent used can be 8 parts, 9 parts, 10 parts, 12 parts, 14 parts, 16 parts, 18 parts, etc.

[0018] In the present invention, the raw materials for preparing the epoxy molding compound are measured by weight, and the amount of the accelerator used can be 0.05 parts, 0.08 parts, 0.1 parts, 0.13 parts, 0.15 parts, 0.18 parts, 0.2 parts, etc.

[0019] Preferably, the modified spherical filler is prepared by the following method:

[0020] The spherical alloy powder and the first organic solvent are mixed, and then the silane coupling agent and the second organic solvent are added and mixed, and then ammonia water is added and stirred, and then tetraethyl silicate is added and stirred continuously, and the mixture is allowed to stand for separation, and then the lower layer product obtained by separation is washed and dried to obtain the modified spherical filler.

[0021] The modified spherical filler provided by the invention has both high magnetic permeability and high insulation.

[0022] Preferably, the spherical alloy powder includes spherical iron-nickel alloy powder, spherical iron-cobalt-nickel alloy powder, spherical iron-vanadium alloy powder, spherical ferrite powder, spherical aluminum-magnesium alloy powder, and spherical iron-based amorphous powder.

[0023] Preferably, the particle size of the spherical alloy powder is 25 to 75 μm, for example, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 75 μm, etc.

[0024] Preferably, the first organic solvent comprises anhydrous ethanol.

[0025] Preferably, the silane coupling agent includes γ-aminopropyltriethoxysilane (KH550) and / or γ-glycidyloxypropyltrimethoxysilane (KH560).

[0026] Preferably, the second organic solvent comprises ethanol.

[0027] Preferably, based on 100% of the spherical alloy powder, the amount of the silane coupling agent is 3-8wt.%, for example, 3wt.%, 4wt.%, 5wt.%, 6wt.%, 7wt.%, 8wt.%, etc.

[0028] Preferably, the amount of ammonia water used is to adjust the pH value of the system to 4-5, such as 4, 4.2, 4.4, 4.5, 4.6, 4.8, 5, etc.

[0029] Preferably, based on 10 g of the spherical alloy powder, the amount of tetraethyl silicate used is 1-3 mL, for example, 1 mL, 1.5 mL, 2 mL, 2.5 mL, 3 mL, etc.

[0030] Preferably, the stirring time is 20-40 min, for example, 20 min, 25 min, 30 min, 35 min, 40 min, etc.

[0031] Preferably, the temperature for continued stirring is 40-60°C, such as 40°C, 45°C, 50°C, 55°C, 60°C, etc., and the time for continued stirring is 3-5h, such as 3h, 4h, 5h, etc.

[0032] Preferably, the washing is performed using ethanol.

[0033] Preferably, the drying temperature is 70-90°C, such as 70°C, 75°C, 80°C, 85°C, 90°C, etc., and the drying time is 1-3h, such as 1h, 2h, 3h, etc.

[0034] Preferably, the epoxy resin includes any one of bisphenol A epoxy resin, bisphenol F epoxy resin, polyphenol glycidyl ether epoxy resin, aliphatic glycidyl ether epoxy resin, and glycidyl ester epoxy resin, or a combination of at least two thereof.

[0035] Preferably, the epoxy resin comprises diglycidyl 4,5-epoxyhexane-1,2-dicarboxylate and / or E51 epoxy resin.

[0036] Preferably, the curing agent includes any one of an amine curing agent, an acid anhydride curing agent, a synthetic resin curing agent, an alkaline curing agent, and an acidic curing agent, or a combination of at least two of them.

[0037] Preferably, the curing agent comprises methylhexahydrophthalic anhydride.

[0038] Preferably, the accelerator includes any one of an imidazole accelerator, a tertiary amine accelerator, and a phenol accelerator, or a combination of at least two of them.

[0039] Preferably, the accelerator comprises 2-ethyl-4-methylimidazole and / or 2-methylimidazole.

[0040] In a second aspect, the present invention provides a method for preparing the epoxy molding compound as described in the first aspect, the preparation method comprising the following steps:

[0041] The modified spherical filler in a prescribed amount is mixed with epoxy resin, and then a curing agent and an accelerator are added, mixed again, and cured to obtain the epoxy molding compound.

[0042] Preferably, the mixing speed is 800-2000r / min, for example 800r / min, 1000r / min, 1200r / min, 1400r / min, 1600r / min, 1800r / min, 2000r / min, etc., and the duration is 3-8min, for example 3min, 4min, 5min, 6min, 8min, etc.

[0043] Preferably, the second mixing has a rotation speed of 800-1000 r / min, such as 800 r / min, 900 r / min, 1000 r / min, etc., and a duration of 1-3 min, such as 1 min, 2 min, 3 min, etc.

[0044] Preferably, the curing temperature is 120-140°C, such as 120°C, 125°C, 130°C, 135°C, 140°C, etc., and the curing time is 1-3h, such as 1h, 2h, 3h, etc.

[0045] In a third aspect, the present invention provides a use of the epoxy molding compound as described in the first aspect in SiP packaging.

[0046] Compared with the prior art, the present invention has the following beneficial effects:

[0047] The present invention uses spherical alloy powder coated with silicon dioxide as filler and epoxy resin as base glue. The prepared epoxy molding compound has excellent electrical insulation performance and electromagnetic shielding performance, high glass transition temperature and low thermal expansion coefficient, and has broad application prospects in SiP structure-function integrated packaging. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 The spherical Fe 30 Ni70 Surface morphology of powder (a), Fe 30 Ni 70 @Surface morphology (b) and cross-sectional views ((c) to (d)) of SiO2 powder.

[0049] Figure 2 Fe provided in Preparation Example 1 30 Ni 70 @Transmission electron microscope image and electron energy spectrum of SiO2 powder.

[0050] Figure 3 The original spherical Fe used in Preparation Example 1 30 Ni 70 Comparison of infrared spectra of powder, modified spherical filler obtained in Preparation Example 1, and modified spherical filler obtained in Preparation Example 6.

[0051] Figure 4 This is a cross-sectional SEM image of the epoxy molding compound provided in Example 1. DETAILED DESCRIPTION

[0052] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0053] Preparation Example 1

[0054] In this preparation example, a modified spherical filler is provided, and the preparation method comprises the following steps:

[0055] First, 10g of spherical Fe 30 Ni 70 The powder (particle size is 35 μm) is dispersed in 50 mL of anhydrous ethanol, and ultrasonic vibration is used to evenly disperse it in a three-necked flask. 0.5 g of silane coupling agent (γ-aminopropyltriethoxysilane) and 50 mL of ethanol are added, and ultrasonic vibration is used to stir and mix them evenly. Then 2 mL of ammonia water is slowly added dropwise and stirred for 30 minutes. Then 2 mL of tetraethyl silicate is slowly added and stirred in a water bath set at 50 ° C for four hours. The solution is allowed to stand to separate the upper white solution, and the lower layer of Fe2O3 coated with SiO2 is placed on the bottom layer. 30 Ni 70 The powder was ultrasonically treated in an ethanol solution for 10 min and then washed with ethanol, which was repeated three times to remove the free silica on the surface. The washed sample was placed in an oven and dried at 80°C for 2 hours to obtain Fe2O3 coated with SiO2 on the surface. 30 Ni 70 @SiO2 powder.

[0056] The spherical Fe 30 Ni 70Surface morphology of powder (a), Fe 30 Ni 70 @The surface morphology (b) and cross-sectional views ((c) to (d)) of SiO2 powder are shown in Figure 1 As shown, it can be seen that the surface of the original material is smooth, and a dense insulating layer is attached to the surface of the material after insulation modification.

[0057] The Fe 30 Ni 70 @ Transmission electron microscope image and electron energy spectrum of SiO2 powder Figure 2 As shown, (b) is an enlarged view of the box area in (a).

[0058] Preparation Example 2

[0059] The difference between this preparation example and preparation example 1 is that the spherical Fe 30 Ni 70 The powder is replaced with an equal weight of spherical Fe 36 Ni 64 powder (particle size 35 μm), and Fe 36 Ni 64 @SiO2 powder.

[0060] Preparation Example 3

[0061] The difference between this preparation example and preparation example 1 is that the spherical Fe 30 Ni 70 The powder is replaced with an equal weight of spherical Fe 50 Ni 50 powder (particle size 35 μm), and Fe 50 Ni 50 @SiO2 powder.

[0062] Preparation Example 4

[0063] The difference between this preparation example and preparation example 1 is that the spherical Fe 30 Ni 70 The particle size of the powder is 15 μm.

[0064] Preparation Example 5

[0065] The difference between this preparation example and preparation example 1 is that the spherical Fe 30 Ni 70 The particle size of the powder is 85 μm.

[0066] Preparation Example 6

[0067] The only difference between this preparation example and preparation example 1 is that no silane coupling agent is added during the preparation process.

[0068] The original spherical Fe used in Preparation Example 1 30 Ni 70 The infrared spectra of the powder, the modified spherical filler obtained in Preparation Example 1 and the modified spherical filler obtained in Preparation Example 6 are compared as shown in FIG. Figure 3 As shown, it can be seen that compared with the modified spherical filler without adding silane coupling agent (Preparation Example 6), the modified spherical filler with added silane coupling agent (Preparation Example 1) has obvious Si-O-Si vibration peak, indicating that the core-shell has a stronger bonding force.

[0069] Comparative Preparation Example 1

[0070] The difference between this preparation example and preparation example 1 is that the spherical Fe 30 Ni 70 The powder is replaced with an equal amount of flake Fe 30 Ni 70 (length is 60-100 μm, thickness is 1-2 μm) to obtain a modified flake filler.

[0071] Examples 1-7

[0072] In Examples 1-7, an epoxy molding compound is provided respectively, and the specific raw materials and amounts (parts by weight) used in the preparation are shown in Table 1.

[0073] Table 1

[0074]

[0075]

[0076] The preparation methods of Examples 1-3 and 5-7 include the following steps:

[0077] According to the formula in Table 1, each raw material was weighed, and the modified spherical filler and the epoxy resin were mechanically mixed using a mixer at a speed of 1000 r / min for 5 min, and then the curing agent and the accelerator were added and mechanically mixed at a speed of 9000 r / min for 2 min; then cured at 140°C for 2 h to obtain the epoxy molding compound; specifically, blocks with cross-sectional areas of 3 mm*3 mm, 7 mm*7 mm and 22.86 mm*10.16 mm were prepared for testing volume resistivity, thermal expansion coefficient and electromagnetic shielding performance, respectively.

[0078] The preparation method of Example 4 is different from the preparation method of Example 1 only in that the curing temperature is 120°C.

[0079] The cross-sectional SEM image of the epoxy molding compound provided in Example 1 of the present invention is as follows: Figure 4 As shown, it can be seen that the modified spherical filler is well dispersed in the epoxy resin.

[0080] Comparative Example 1

[0081] The difference between this comparative example and Example 1 is that the modified spherical filler (Fe 30 Ni 70 @SiO2 powder) is replaced with an equal weight of spherical Fe 30 Ni 70 Powder (i.e. unmodified Fe 30 Ni 70 Original powder, particle size 35 μm).

[0082] Comparative Example 2

[0083] The difference between this comparative example and Example 2 is that the modified spherical filler (Fe 36 Ni 64 @SiO2 powder) is replaced with an equal weight of spherical Fe 36 Ni 64 Powder (i.e. unmodified Fe 36 Ni 64 Original powder, particle size 35 μm).

[0084] Comparative Example 3

[0085] The difference between this comparative example and Example 3 is that the modified spherical filler (Fe 50 Ni 50 @SiO2 powder) is replaced with an equal weight of spherical Fe 50 Ni 50 Powder (i.e. unmodified Fe 50 Ni 50 Original powder, particle size 35 μm).

[0086] Comparative Example 4

[0087] The only difference between this comparative example and Example 1 is that the amount of the modified spherical filler is 220 parts by weight.

[0088] Comparative Example 5

[0089] The only difference between this comparative example and Example 1 is that the amount of the modified spherical filler used is 120 parts by weight.

[0090] Comparative Example 6

[0091] The only difference between this comparative example and Example 1 is that the modified spherical filler is replaced by the modified flake filler provided in Comparative Preparation Example 1. Since the flake filler has poor surface fluidity, the amount thereof is 70 parts by weight.

[0092] The epoxy molding compound provided in the embodiment and the comparative example was tested for performance, and the testing method was as follows:

[0093] (1) Volume resistivity: tested with a high resistance meter;

[0094] (2) Viscosity: tested using a rotational rheometer;

[0095] (3) Thermal expansion coefficient: tested by a thermomechanical analyzer; thermal expansion coefficient 1 is tested at 25-200°C, and thermal expansion coefficient 2 is tested at 200-300°C;

[0096] (4) Electromagnetic shielding performance: 8.2-12 GHz test using a vector network analyzer;

[0097] (5) Glass transition temperature: tested using a dynamic thermomechanical analyzer.

[0098] The performance test results are shown in Table 2.

[0099] Table 2

[0100]

[0101]

[0102] The “\” in Table 2 indicates that the corresponding test was not conducted (since the volume resistivity of the epoxy molding compound provided in the relevant comparative example could not meet the requirements, it was meaningless to conduct other tests, so no test was conducted).

[0103] It can be seen from Table 2 that the epoxy molding compounds provided in Examples 1-4 of the present invention all have excellent electrical insulation properties (volume resistivity: 5.81E+11~2.99E+12Ω·cm) and electromagnetic shielding properties (20.2~26.1dB), and at the same time have a higher glass transition temperature, lower thermal expansion coefficient and viscosity.

[0104] Compared with Examples 1-3, the electrical insulation properties of the epoxy molding compounds provided in Comparative Examples 1-3 are significantly reduced.

[0105] Compared with Example 1, the viscosity of the epoxy molding compound provided in Comparative Example 4 is significantly increased, making it difficult to cast and mold. The viscosity of the epoxy molding compound provided in Comparative Example 5 is reduced, but the electromagnetic shielding performance is very poor (only 11 dB). The electrical insulation and electromagnetic shielding performance of the epoxy molding compound provided in Comparative Example 6 are significantly reduced, and the thermal expansion coefficient is increased.

[0106] The applicant declares that the present invention illustrates the epoxy molding compound and its preparation method and application through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the raw materials selected by the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. An epoxy molding compound, characterized in that: The raw materials for preparing the epoxy molding compound include the following components in parts by weight: The modified spherical filler is a spherical alloy powder with silicon dioxide coated on the surface.

2. The epoxy molding compound according to claim 1, characterized in that: The modified spherical filler is prepared by the following method: The spherical alloy powder and the first organic solvent are mixed, and then the silane coupling agent and the second organic solvent are added and mixed, and then ammonia water is added and stirred, and then tetraethyl silicate is added and stirred continuously, and the mixture is allowed to stand for separation, and then the lower layer product obtained by separation is washed and dried to obtain the modified spherical filler.

3. The epoxy molding compound according to claim 2, characterized in that: The spherical alloy powder includes spherical iron-nickel alloy powder, spherical iron-cobalt-nickel alloy powder, spherical iron-vanadium alloy powder, spherical ferrite powder, spherical aluminum-magnesium alloy powder, and spherical iron-based amorphous powder; Preferably, the particle size of the spherical alloy powder is 25-75 μm; Preferably, the first organic solvent comprises anhydrous ethanol; Preferably, the silane coupling agent includes γ-aminopropyltriethoxysilane and / or γ-glycidyloxypropyltrimethoxysilane; Preferably, the second organic solvent comprises ethanol; Preferably, based on 100% of the spherical alloy powder, the amount of the silane coupling agent is 3-8 wt.%; Preferably, the amount of ammonia water is used to adjust the pH value of the system to 4 to 5; Preferably, based on 10 g of the spherical alloy powder, the amount of tetraethyl silicate used is 1-3 mL.

4. The epoxy molding compound according to claim 2 or 3, characterized in that: The stirring time is 20-40min; Preferably, the temperature of the continued stirring is 40-60°C, and the time of continued stirring is 3-5h; Preferably, the washing is performed by washing with ethanol; Preferably, the drying temperature is 70-90° C., and the drying time is 1-3 hours.

5. The epoxy molding compound according to any one of claims 1 to 4, characterized in that: The epoxy resin includes any one of bisphenol A epoxy resin, bisphenol F epoxy resin, polyphenol glycidyl ether epoxy resin, aliphatic glycidyl ether epoxy resin, and glycidyl ester epoxy resin, or a combination of at least two thereof; Preferably, the epoxy resin comprises diglycidyl 4,5-epoxyhexane-1,2-dicarboxylate and / or E51 epoxy resin.

6. The epoxy molding compound according to any one of claims 1 to 5, characterized in that: The curing agent includes any one of an amine curing agent, an acid anhydride curing agent, a synthetic resin curing agent, an alkaline curing agent, and an acidic curing agent, or a combination of at least two thereof; Preferably, the curing agent comprises methylhexahydrophthalic anhydride.

7. The epoxy molding compound according to any one of claims 1 to 6, characterized in that: The accelerator includes any one of an imidazole accelerator, a tertiary amine accelerator, and a phenol accelerator, or a combination of at least two thereof; Preferably, the accelerator comprises 2-ethyl-4-methylimidazole and / or 2-methylimidazole.

8. A method for preparing the epoxy molding compound according to any one of claims 1 to 7, characterized in that: The preparation method comprises the following steps: The modified spherical filler in a prescribed amount is mixed with epoxy resin, and then a curing agent and an accelerator are added, mixed again, and cured to obtain the epoxy molding compound.

9. The preparation method according to claim 8, characterized in that: The mixing speed is 800-2000r / min, and the mixing time is 3-8min; Preferably, the speed of the second mixing is 800-1000 r / min, and the duration is 1-3 min; Preferably, the curing temperature is 120-140° C., and the curing time is 1-3 hours.

10. Use of the epoxy molding compound according to any one of claims 1 to 7 in SiP packaging.

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