Epoxy molding compound and preparation method thereof

Abstract

The invention relates to the technical field of electronic packaging materials, and discloses an epoxy molding compound and a preparation method thereof. The epoxy molding compound is prepared from the following raw materials in percentage by weight: 70 to 90 percent of filler, 5 to 15 percent of epoxy resin, 3.1 to 10.5 percent of phenolic resin-stearylamine intermediate, 0.2 to 0.8 percent of catalyst, 1 to 5 percent of stress absorbent, 0.2 to 2 percent of coupling agent, 0.1 to 1.2 percent of release agent and 0.1 to 0.5 percent of coloring agent. According to the invention, by adding the phenolic resin-stearylamine intermediate into the epoxy molding compound, the final volume resistivity of the epoxy molding compound can be reduced to 108-1011 omega.cm, and by reducing the volume resistivity and improving the conductivity of the material, rapid release of static electricity is realized, and the problem of electrostatic adsorption is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic packaging materials, in particular to an epoxy molding compound and a preparation method thereof. Background Art

[0002] Epoxy molding compound, also known as epoxy resin molding compound, is a thermosetting chemical material used for semiconductor packaging. It is a powdered molding compound composed of epoxy resin as the base resin, high-performance phenolic resin as the curing agent, silica powder and other fillers, and various additives. It is a key raw material for back-end packaging. Currently, over 95% of microelectronic devices are epoxy-molded. Epoxy molding compound protects chips from external environmental influences, resists external solvents, moisture, and impact, and ensures electrical insulation between the chip and the outside world.

[0003] After the chip is encapsulated with epoxy molding compound, the single unit is easily attached to the inner wall of the metal iron barrel due to its own static electricity, which requires a lot of time and effort to clean, thereby reducing production efficiency. In addition, electrostatic discharge has the following hazards: (1) There are thin dielectric layers in the core structure of semiconductor devices, such as the gate oxide layer of SMT devices. The high voltage generated by electrostatic discharge can easily break through these dielectric layers, causing the device to short circuit or leak. (2) In the semiconductor manufacturing process, due to the use of a large number of highly insulating quartz and polymer materials, static electricity is easily generated after friction. The adsorption of static electricity will attract floating dust in the surrounding environment. These floating dusts adhere to the surface of the chip, which will change the impedance between the lines and affect the function and life of the semiconductor device. (3) Electrostatic discharge will increase the defect rate of semiconductor devices, resulting in more raw materials and energy input in the production process, as well as an increase in the workload of testing and screening, thereby increasing manufacturing costs. In addition, static electricity can easily cause equipment to shut down, unexpected operation or restart, resulting in production interruption and affecting production progress. Therefore, how to reduce the generation of static electricity when encapsulating semiconductors with epoxy molding compound is an urgent problem to be solved. Summary of the Invention

[0004] In view of this, the present invention provides an epoxy molding compound and a preparation method thereof to solve the problem that conventional epoxy molding compounds easily generate static electricity when packaging semiconductors, thereby reducing production efficiency.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] On the one hand, the present invention provides an epoxy molding compound, comprising the following raw materials in percentage by weight: 70-90% filler, 5-15% epoxy resin, 3.1-10.5% phenolic resin-stearylamine intermediate, 0.2-0.8% catalyst, 1-5% stress absorber, 0.2-2% coupling agent, 0.1-1.2% release agent and 0.1-0.5% colorant.

[0007] Preferably, the phenolic resin-stearylamine intermediate consists of stearylamine and phenolic resin, and the mass ratio of stearylamine to phenolic resin is 1:4-8.

[0008] Preferably, the phenolic resin includes one or more of MAR phenolic resin, XYLOK phenolic resin, PN phenolic resin, OCN phenolic resin and MFN phenolic resin.

[0009] Preferably, the particle size of the phenolic resin-stearylamine intermediate is ≤0.3 mm.

[0010] Preferably, the filler includes one or more of SiO2 micropowder, Al2O3 micropowder, AlN micropowder, SiC micropowder and BN micropowder.

[0011] Preferably, the epoxy resin includes one or more of BP epoxy resin, MAR epoxy resin, EOCN epoxy resin, DCPD epoxy resin and MFN epoxy resin.

[0012] Preferably, the catalyst includes one or more of imidazole and its derivatives, triphenylphosphine and its derivatives, organic amine compounds, and phosphonium salt compounds.

[0013] Preferably, the stress absorber includes one or more of carboxyl-terminated liquid nitrile rubber (CTBN), silicone-modified epoxy resin, core-shell rubber (CSR), and silicone block copolymer.

[0014] Preferably, the release agent includes one or more of polyethylene wax, oxidized polyethylene wax, montan E wax, Fischer-Tropsch wax, vegetable wax, fatty acid glyceride wax, and maleic anhydride grafted modified wax.

[0015] Preferably, the colorant includes one or more of iron yellow, carbon black, titanium dioxide, zinc oxide, and lithopone.

[0016] Preferably, the coupling agent is a silane coupling agent and / or a titanate coupling agent.

[0017] Preferably, the silane coupling agent includes one or more of 3-mercaptopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, and bis-[3-(triethoxysilyl)propyl]-tetrasulfide.

[0018] Preferably, the titanate coupling agent includes one or more of isopropyl tris(dioctyl pyrophosphate) titanate and isopropyl dioleate oxy(dioctyl phosphate titanate).

[0019] On the other hand, the present invention also provides a method for preparing the epoxy molding compound described in any one of the above, comprising the following steps:

[0020] (1) preparing a phenolic resin-stearylamine intermediate;

[0021] (2) mixing a filler, an epoxy resin, a phenolic resin-stearylamine intermediate, a catalyst, a stress absorber, a coupling agent, a release agent, and a colorant to obtain a premix;

[0022] (3) The premix is ​​melt-extruded to obtain an epoxy molding compound.

[0023] Preferably, the steps of preparing the phenolic resin-stearylamine intermediate are as follows:

[0024] A. Melting the phenolic resin to obtain liquid phenolic resin;

[0025] B. mixing the liquid phenolic resin and stearylamine to obtain a mixture;

[0026] C. The mixture is cooled and then crushed to obtain a phenolic resin-stearylamine intermediate.

[0027] Preferably, the mixing time of the liquid phenolic resin and stearylamine is 30-60 minutes.

[0028] Preferably, the cooling is firstly naturally cooling to room temperature, then rapidly cooling at -10 to -5°C, and staying at -10 to -5°C for 12 hours.

[0029] The present invention provides an epoxy molding compound and a preparation method thereof. Compared with the prior art, the present invention has the following advantages:

[0030] The stearylamine in the phenolic resin-stearylamine intermediate of the present invention is as an antistatic agent. On the one hand, stearylamine has a hydrophobic group, and the non-polar part of other raw materials of epoxy molding compound interacts so that stearylamine can be preferably combined on the surface or inside of epoxy molding compound; On the other hand, stearylamine has hydrophilicity, and this amphiphilic structure makes stearylamine have the characteristic of surfactant, can form an adsorption layer of directional arrangement on the surface of epoxy molding compound, reduce the static accumulation tendency on the surface of epoxy molding compound, and can adsorb moisture in the air, form a layer of water film on the surface of epoxy molding compound, this layer of water film can play the effect of conductivity, so that static charge can be conducted to other positions or the surrounding environment on the surface of epoxy molding compound by water film, thereby reducing static accumulation, reducing static potential. In addition, the amino group present in stearylamine can chemically react or form hydrogen bond with some groups in epoxy molding compound under certain conditions, further enhance its compatibility and bonding force with epoxy molding compound, thereby more effectively play antistatic effect, and make antistatic effect have persistence. Furthermore, stearylamine can fill tiny pores and rough areas on the surface of epoxy molding compounds, making them smoother and flatter. This reduces charge accumulation and electrostatic discharge caused by surface roughness, thereby lowering the generation of static electricity. Furthermore, stearylamine, when mixed with other raw materials in the form of a phenolic resin-stearylamine intermediate, can be more evenly dispersed in the epoxy molding compound, allowing the stearylamine to more fully exert its antistatic properties.

[0031] The present invention can reduce the volume resistivity of the final epoxy molding compound to 10 by adding phenolic resin-stearylamine intermediate into the epoxy molding compound. 8 -10 11 Ω·cm, by reducing the volume resistivity and improving the conductivity of the material, the rapid release of static electricity can be achieved, thereby solving the problem of static adsorption. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0033] Figure 1 Schematic diagram of the atomic particle adhesion of the SOT23 device. DETAILED DESCRIPTION

[0034] The present invention will be described below by specific embodiment, and it will be appreciated by those skilled in the art that the specific embodiment below is only for illustrative purposes, and does not limit the scope of the present invention in any way. In addition, in the following examples, unless otherwise stated, the reagent and equipment used are all commercially available. If in the following examples, concrete treatment conditions and treatment process are not clearly described, then conditions and methods well known in the art can be adopted to process.

[0035] In one aspect of the present invention, an epoxy molding compound is provided, comprising the following raw materials in percentage by weight: 70-90% filler, 5-15% epoxy resin, 3.1-10.5% phenolic resin-stearylamine intermediate, 0.2-0.8% catalyst, 1-5% stress absorber, 0.2-2% coupling agent, 0.1-1.2% release agent and 0.1-0.5% colorant.

[0036] In some embodiments of the present invention, the epoxy molding compound includes a filler, and the filler is added in an amount of 70-90%, specifically 70%, 75%, 80%, 85%, and 90%. The filler includes one or more of SiO2 micropowder, Al2O3 micropowder, AlN micropowder, SiC micropowder, and BN micropowder, wherein the SiO2 micropowder can be crystalline SiO2 micropowder and / or molten SiO2 micropowder. The filler has a particle size of less than 150 μm, with an average particle size of 75 μm. By limiting the filler particle size to this range, good fluidity of the epoxy molding compound can be maintained.

[0037] In some embodiments of the present invention, the epoxy molding compound includes epoxy resin, and the added amount of the epoxy resin is 5-15%, specifically 5%, 10%, and 15%. The epoxy resin includes one or more of BP epoxy resin, MAR epoxy resin, EOCN epoxy resin, DCPD epoxy resin, and MFN epoxy resin. The epoxy resin has the following structural formula:

[0038]

[0039] In some embodiments of the present invention, the epoxy molding compound includes a phenolic resin-stearylamine intermediate, and the amount of the phenolic resin-stearylamine intermediate added is 3.1-10.5%, specifically 3.1%, 4%, 5%, 6%, 8%, 10%, and 10.5%. The phenolic resin-stearylamine intermediate is composed of stearylamine and phenolic resin, and the mass ratio of stearylamine to phenolic resin is 1:4-8, specifically 1:4, 1:5, 1:6, 1:7, and 1:8.

[0040] In some embodiments of the present application, the particle size of the phenolic resin-stearylamine intermediate is ≤0.3mm. The phenolic resin-stearylamine intermediate with a particle size ≤0.3mm can be more uniformly dispersed in the raw material, so that it can better exert its antistatic performance.

[0041] The phenolic resin includes one or more of MAR phenolic resin, XYLOK phenolic resin, PN phenolic resin, OCN phenolic resin, and MFN phenolic resin. The structural formula of the phenolic resin is as follows:

[0042]

[0043] In the present application, stearylamine is used as an antistatic agent, and the phenolic resin and stearylamine are used to form a phenolic resin-stearylamine intermediate with a specific mass ratio due to the good compatibility of the phenolic resin and stearylamine. The phenolic resin-stearylamine intermediate is used as one of the raw materials, and is combined with other raw materials to obtain an epoxy plastic packaging material. The antistatic agent stearylamine can be uniformly dispersed in the epoxy plastic packaging material, so that it can fully exert its antistatic effect.

[0044] In some embodiments of the present application, the epoxy plastic packaging material includes a catalyst, and the addition amount of the catalyst is 0.2-0.8%, specifically 0.2%, 0.4%, 0.6%, 0.8%, etc. The catalyst includes one or more of imidazole and its derivatives, triphenylphosphine and its derivatives, organic amine compounds, and phosphonium salt compounds.

[0045] In some embodiments of the present application, the epoxy plastic packaging material includes a stress absorber, and the addition amount of the stress absorber is 1-5%, specifically 1%, 2%, 3%, 4%, 5%, etc. The stress absorber includes one or more of carboxyl-terminated liquid butyl nitrile rubber (CTBN), silicone-modified epoxy resin, core-shell structure rubber (CSR), and silicone-based block copolymer.

[0046] In some embodiments of the present application, the epoxy plastic packaging material includes a release agent, and the addition amount of the release agent is 0.1-1.2%, specifically 0.1%, 0.5%, 0.8%, 1%, 1.2%, etc. The release agent includes one or more of polyethylene wax, oxidized polyethylene wax, montan E wax, Fischer-Tropsch synthesis wax, vegetable wax, fatty acid glyceride wax, and maleic anhydride grafted modified wax.

[0047] In some embodiments of the present application, the epoxy plastic packaging material includes a colorant, and the addition amount of the colorant is 0.1-0.5%, specifically 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, etc. The colorant includes one or more of iron yellow, carbon black, titanium white powder, zinc oxide, and zinc white.

[0048] In some embodiments of the present application, the epoxy encapsulant comprises a coupling agent, and the coupling agent is added in an amount of 0.2-2%, specifically 0.2%, 0.5%, 1%, 1.5%, 2%, etc. The coupling agent is a silane coupling agent and / or a titanate coupling agent. The silane coupling agent comprises one or more of 3-mercaptopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, and bis-[3-(triethoxysilyl)propyl]-tetrasulfide; and the titanate coupling agent comprises one or more of isopropyl tri(dioctylpyrophosphato) titanate and isopropyl dioleatoxy (dioctylphosphato titanate).

[0049] It should be noted that the filler, the epoxy resin, the phenolic resin, the stearylamine, the catalyst, the stress absorber, the coupling agent, the release agent, and the colorant in the present application can be purchased from the market, and thus no special limitation is imposed on the raw materials.

[0050] In another aspect of the present application, the present application further provides a preparation method of the epoxy encapsulant, comprising the following steps:

[0051] (1) preparing a phenolic resin-stearylamine intermediate;

[0052] (2) mixing the filler, the epoxy resin, the phenolic resin-stearylamine intermediate, the catalyst, the stress absorber, the coupling agent, the release agent, and the colorant to obtain a premix;

[0053] (3) melt-extruding the premix to obtain the epoxy encapsulant.

[0054] In the present application, the phenolic resin-stearylamine intermediate is prepared first.

[0055] In some embodiments of the present application, the step of preparing the phenolic resin-stearylamine intermediate is as follows:

[0056] A. melting the phenolic resin to obtain a liquid phenolic resin;

[0057] B. mixing the liquid phenolic resin and the stearylamine to obtain a mixture;

[0058] C. crushing the mixture after cooling to obtain the phenolic resin-stearylamine intermediate.

[0059] Since the purpose of melting is to melt the phenolic resin into a liquid state to facilitate subsequent mixing with stearylamine, the melting temperature in step A is not particularly limited and can be adjusted according to the melting point of the specific phenolic resin. The melting point of the phenolic resin varies depending on the molecular structure, formulation, and production process, but is generally within the range of 50-150°C. Therefore, it is preferred to limit the melting temperature to greater than 150°C, for example, 160°C, 170°C, 175°C, etc.

[0060] The purpose of mixing in step B is to uniformly mix the liquid phenolic resin and stearylamine, so there is no particular limitation on the mixing time, and the mixing can be stirring mixing, and the stirring mixing time is preferably 30-60 minutes, specifically 30 minutes, 40 minutes, 50 minutes, 60 minutes, etc.

[0061] The cooling in step C is first naturally cooled to room temperature, then rapidly cooled at -10 to -5°C, and kept at -10 to -5°C for 12 hours. The rapid cooling can maintain the polymer molecular chains and prevent the molecular chains from breaking, thereby maintaining the stability of the system. There is no special limitation on the pulverization method, for example, it can be ground and pulverized, and then passed through a 50-mesh sieve, and the sieve under the sieve is the phenolic resin-stearylamine intermediate.

[0062] In the present invention, after obtaining the phenolic resin-stearylamine intermediate, filler, epoxy resin, phenolic resin-stearylamine intermediate, catalyst, stress absorber, coupling agent, release agent and colorant are mixed to obtain a premix.

[0063] In some embodiments of the present invention, before mixing the raw materials, each raw material may be ground and then passed through a 50-mesh sieve. The undersize fraction, i.e., the raw material particle size is ≤ 0.3 mm, is removed to ensure a more uniform mixing of the raw materials. Furthermore, the mixing method is not particularly limited, and for example, stirring can be used, as long as uniform mixing is ensured.

[0064] In the present invention, after the premix is ​​obtained, the premix is ​​melt-extruded to obtain the epoxy molding compound.

[0065] In some embodiments of the present application, the premix is subjected to melt extrusion, in particular, the premix is fed into an extruder for melt mixing and extrusion. The melt mixing process can be performed in a conventional manner, and no special limitation is imposed thereon. For example, during the melt mixing process, the parameters of the extruder are set to meet the following conditions: the main motor speed is 200-250 rpm, for example, it can be 200 rpm, 220 rpm, 240 rpm, and 250 rpm, etc.; the feeding speed is 9-15 rpm, for example, it can be 9 rpm, 12 rpm, and 15 rpm, etc.; and the extrusion is performed after passing through five temperature zones of 60°C, 80°C, 80°C, 50°C, and 60°C in sequence from the feeding port to the die.

[0066] In some embodiments of the present application, after the premix is subjected to melt extrusion, the extrudate is further subjected to cooling and crushing. The cooling can be natural cooling to room temperature, and no special limitation is imposed on the particle size of the crushed material, which can be adjusted according to the actual use.

[0067] In some embodiments of the present application, the epoxy plastic packaging material is stored in a low-temperature environment, for example, at 0-5°C, to maintain its stability.

[0068] The technical solutions in the present application will be described below in detail with reference to specific examples. The examples of the present application are only for illustration, and all other examples obtained by those skilled in the art without creative labor fall within the scope of the present application.

[0069] Example 1

[0070] The present example provides an epoxy plastic packaging material, which is composed of the following raw materials in weight percentage: filler 72%, epoxy resin 12.6%, phenolic resin-stearylamine intermediate 10%, catalyst 0.6%, stress absorber 2%, coupling agent 1.5%, release agent 1.0%, and colorant 0.3%.

[0071] The filler is fused silicon powder, the epoxy resin is EOCN epoxy resin (manufacturer: Changchun Artificial Resin Factory Co., Ltd. in Taiwan, China, model: CNE195XL8), the catalyst is triphenylphosphine, the stress absorber is methyltrimethoxysilane modified epoxy resin, the coupling agent is 3-mercaptopropyltrimethoxysilane, the release agent is Montan E wax, the colorant is carbon black, and the phenolic resin-stearylamine intermediate is composed of stearylamine and phenolic resin in a mass ratio of 1:6, and the phenolic resin is PN phenolic resin (manufacturer: Shengquan New Material Co., Ltd. in Shandong, China, model: PF-8011).

[0072] The preparation method of the epoxy plastic packaging material is as follows:

[0073] (1) stirring and mixing the liquid phenolic resin obtained by melting the phenolic resin and stearylamine for 45 minutes, cooling the obtained mixture naturally to room temperature, then rapidly cooling it at -5°C, and keeping it at -5°C for 12 hours, crushing it and passing it through a 50-mesh sieve, and taking the sieve under the sieve to obtain a phenolic resin-stearylamine intermediate;

[0074] (2) mixing all the raw materials to obtain a premix;

[0075] (3) The premix is ​​fed into an extruder, and the parameters of the extruder are set to meet the following conditions: the main engine speed is 220 rpm, the feeding speed is 9 rpm, and the premix is ​​extruded from the feed port to the die head through five temperature zones of 60°C, 80°C, 80°C, 50°C, and 60°C. The extrudate is cooled to room temperature and then crushed to obtain the epoxy molding compound.

[0076] Example 2

[0077] This embodiment is basically the same as embodiment 1, with the only difference being that the main engine speed of the extruder is 240 rpm.

[0078] Example 3

[0079] This embodiment is substantially the same as embodiment 1, with the only difference being that the extruder feeding speed is 12 rpm.

[0080] Example 4

[0081] This embodiment is substantially the same as embodiment 1, with the only difference being that the phenolic resin-stearylamine intermediate is composed of stearylamine and phenolic resin in a mass ratio of 1:1.

[0082] Example 5

[0083] This embodiment is substantially the same as embodiment 1, with the only difference being that the phenolic resin-stearylamine intermediate is composed of stearylamine and phenolic resin in a mass ratio of 1:10.

[0084] Comparative Example 1

[0085] This comparative example is substantially the same as Example 1, except that stearylamine is not added.

[0086] Comparative Example 2

[0087] This comparative example is substantially the same as Example 1, except that stearylamine is replaced by antistatic agent SN, that is, stearylamine is replaced by octadecyl dimethyl hydroxyethyl quaternary ammonium nitrate.

[0088] Comparative Example 3

[0089] This comparative example is substantially the same as Example 1, with the only difference being that stearylamine is replaced by a conductive filler, and the conductive filler is carbon black.

[0090] Comparative Example 4

[0091] This comparative example is basically the same as Example 1, the only difference being that stearylamine is replaced by an ionic auxiliary agent, and the ionic auxiliary agent is an inorganic flame retardant zinc oxide.

[0092] Comparative Example 5

[0093] This comparative example is basically the same as Example 1, the only difference being that stearylamine is replaced by an ionic auxiliary agent, and the ionic auxiliary agent is a coupling agent 3-mercaptopropyltrimethoxysilane.

[0094] Comparative Example 6

[0095] This comparative example is basically the same as Example 1, except that stearylamine is replaced by an ion capture agent, which is magnesium aluminum hydrotalcite.

[0096] The volume resistivity of the epoxy molding compounds of Examples 1-5 and Comparative Examples 1-6 was tested, and the results are shown in Table 1. The volume resistivity test was based on GB / T 31838.2 Dielectric and resistive properties of solid insulating materials Part 2: Resistive properties (DC method) Volume resistance and volume resistivity.

[0097] Table 1

[0098] Volume resistivity (Ω·cm) Water absorption (%) Example 1 <![CDATA[2.3*10 8 ]]> 0.63 Example 2 <![CDATA[4.5*10 9 ]]> 0.61 Example 3 5.5*10 9 ]]> 0.62 Example 4 <![CDATA[9.3*10 13 ]]> 0.63 Example 5 <![CDATA[6.7*10 12 ]]> 0.62 Comparative Example 1 <![CDATA[2.2*10 15 ]]> 0.60 Comparative Example 2 <![CDATA[5.6*10 14 ]]> 0.84 Comparative Example 3 <![CDATA[7.2*10 15 ]]> 0.62 Comparative Example 4 <![CDATA[9.1*10 15 ]]> 0.63 Comparative Example 5 <![CDATA[6.2*10 14 ]]> 0.62 Comparative Example 6 <![CDATA[3.2*10 15 ]]> 0.64

[0099] Compared to Examples 1-5, the epoxy molding compounds of Comparative Examples 1-6 still have the problem of electrostatic adsorption. As can be seen from Table 1, the volume resistivity of the epoxy molding compound of the present invention is significantly reduced, thereby effectively improving the conductive properties of the epoxy molding compound, achieving rapid static discharge, and thus solving the problem of electrostatic adsorption. From Example 1 and Comparative Example 2, it can be concluded that when the antistatic agent is octadecyl dimethyl hydroxyethyl quaternary ammonium nitrate, the resulting epoxy molding compound not only has a high volume resistivity, but also exceeds the water absorption standard (the use requirement is less than 0.7%). However, when the antistatic agent is stearylamine, the water absorption meets the use requirements and can significantly reduce the volume resistivity.

[0100] In addition, the electronic semiconductor SOT23 was encapsulated using the epoxy molding compound of Example 1 and Comparative Example 1, and after the same mold injection molding, post-curing, electroplating, deburring, laser marking, cutting and bending, inspection and other steps, a single SOT23 device was formed. Figure 1As shown in FIG, a schematic diagram of the atomic particle adhesion of the SOT23 device is shown. It can be seen from the figure that, compared with Comparative Example 1 (right figure), the number of atomic particles adhering to the SOT23 device obtained by encapsulating the electronic semiconductor SOT23 with the epoxy molding compound of Example 1 (left figure) is significantly reduced (from more than 100 to 2-12), indicating that the epoxy molding compound of the present invention can effectively solve the problem of electrostatic adsorption.

[0101] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. An epoxy molding compound, characterized in that: The invention comprises the following raw materials in percentage by weight: 70-90% of filler, 5-15% of epoxy resin, 3.1-10.5% of phenolic resin-stearylamine intermediate, 0.2-0.8% of catalyst, 1-5% of stress absorber, 0.2-2% of coupling agent, 0.1-1.2% of release agent and 0.1-0.5% of colorant.

2. The epoxy molding compound according to claim 1, wherein The phenolic resin-stearylamine intermediate is composed of stearylamine and phenolic resin; The mass ratio of the stearylamine to the phenolic resin is 1:4-8.

3. The epoxy molding compound according to claim 2, wherein: The phenolic resin includes one or more of MAR phenolic resin, XYLOK phenolic resin, PN phenolic resin, OCN phenolic resin and MFN phenolic resin.

4. The epoxy molding compound according to any one of claims 1 to 3, characterized in that: The particle size of the phenolic resin-stearylamine intermediate is ≤0.3 mm.

5. The epoxy molding compound according to claim 1, wherein: The filler includes one or more of SiO2 micropowder, Al2O3 micropowder, AlN micropowder, SiC micropowder and BN micropowder.

6. The epoxy molding compound according to claim 1, wherein: The epoxy resin includes one or more of BP epoxy resin, MAR epoxy resin, EOCN epoxy resin, DCPD epoxy resin and MFN epoxy resin; The catalyst includes one or more of imidazole and its derivatives, triphenylphosphine and its derivatives, organic amine compounds, and phosphonium salt compounds; The stress absorber includes one or more of carboxyl-terminated liquid nitrile rubber, silicone-modified epoxy resin, core-shell structure rubber, and silicone block copolymer; The release agent includes one or more of polyethylene wax, oxidized polyethylene wax, montan E wax, Fischer-Tropsch wax, vegetable wax, fatty acid glyceride wax, and maleic anhydride grafted modified wax; The colorant includes one or more of iron yellow, carbon black, titanium dioxide, zinc oxide, and lithopone.

7. The epoxy molding compound according to claim 1, wherein: The coupling agent is a silane coupling agent and / or a titanate coupling agent; The silane coupling agent includes one or more of 3-mercaptopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, and bis-[3-(triethoxysilyl)propyl]-tetrasulfide; The titanate coupling agent includes one or more of isopropyl tris(dioctyl pyrophosphate acyloxy) titanate and isopropyl dioleate oxy (dioctyl phosphate acyloxy titanate).

8. A method for preparing the epoxy molding compound according to any one of claims 1 to 7, characterized in that: The following steps are involved: (1) preparing a phenolic resin-stearylamine intermediate; (2) mixing a filler, an epoxy resin, a phenolic resin-stearylamine intermediate, a catalyst, a stress absorber, a coupling agent, a release agent, and a colorant to obtain a premix; (3) The premix is ​​melt-extruded to obtain an epoxy molding compound.

9. The method for preparing the epoxy molding compound according to claim 8, wherein: The steps of preparing the phenolic resin-stearylamine intermediate are as follows: A. Melting the phenolic resin to obtain liquid phenolic resin; B. mixing the liquid phenolic resin and stearylamine to obtain a mixture; C. The mixture is cooled and then crushed to obtain a phenolic resin-stearylamine intermediate.

10. The method for preparing the epoxy molding compound according to claim 9, wherein: The mixing time of the liquid phenolic resin and stearylamine is 30-60 minutes; The cooling is to first cool naturally to room temperature, then cool rapidly at -10 to -5°C, and stay at -10 to -5°C for 12 hours.

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