A heat conductive epoxy resin plastic encapsulating material for encapsulating materials and a preparation method thereof

Abstract

The application discloses a kind of heat-conducting epoxy resin plastic packaging materials for packaging material and preparation method thereof, belong to epoxy resin material preparation technical field.The preparation method includes the following steps: polyurethane is coated with silicon carbide, curing agent composition and epoxy resin composition are mixed according to the weight ratio 15~21:20~23:30~36 after vacuum degassing treatment, then heated to 90~100 ℃ and cured for 3~4 hours to obtain heat-conducting epoxy resin plastic packaging material.The heat-conducting epoxy resin plastic packaging material obtained by mixing and curing reaction of polyurethane coated with silicon carbide, curing agent composition and epoxy resin composition has good heat-conducting performance and mechanical properties.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of epoxy resin material preparation, and particularly relates to a heat-conducting epoxy resin plastic packaging material for packaging materials and a preparation method thereof. BACKGROUND

[0002] With the rapid development of electronic technology, the integration of electronic devices is continuously improved, and packaging technology, as an important link between chips and the external environment, is increasingly valued. Packaging materials play a crucial role in ensuring the performance of electronic components, extending their service life, and improving production efficiency. Electronic packaging materials refer to the peripheral sealing layer of electronic components, which plays a key role in supporting electronic components and interconnecting key lines, isolating the external environment, conducting and dissipating heat from electronic components, etc. Based on these functions, excellent electronic packaging materials need to have excellent heat dissipation performance and good thermal expansion coefficient matching, as well as insulation, flame retardation, etc. According to the difference of material components, electronic packaging materials can be roughly divided into metal-based electronic packaging materials, ceramic-based electronic packaging materials and polymer-based electronic packaging materials. Metal-based electronic packaging materials were developed earlier and have the characteristics of high thermal conductivity and high strength. However, the shortcomings of traditional metal-based packaging materials, such as high density and difficult processing, have affected their widespread application. Ceramic-based electronic packaging materials are a kind of airtight electronic packaging materials, mainly including alumina, aluminum nitride, etc. Polymer-based electronic packaging materials are currently the most widely used and fastest developing electronic packaging materials, which have the advantages of small density, fast molding, low manufacturing cost, etc., and can adapt to various complex packaging molding structures, and are an important type of electronic packaging materials for realizing the miniaturization, light weight and low cost of electronic products.

[0003] Epoxy plastic packaging material is a polymer-based electronic packaging material widely used in semiconductor device packaging, which has the advantages of reliable stability, low cost, simple production process and suitability for mass production. However, due to the low thermal conductivity of epoxy resin material, the heat generated by electronic components is difficult to dissipate quickly, which can easily lead to overheating of electronic components, thereby affecting the performance, stability and life of electronic components.

[0004] Patent CN112409757A discloses a high-thermal-conductivity epoxy plastic packaging material for high-power module packaging and a preparation method thereof. The invention uses cheap urea, boric acid and spherical silica commonly used in the field as raw materials to prepare SiO2@BN particles with core-shell structure and high thermal conductivity with large particle size, which are applied to the preparation of high-thermal-conductivity EMC, greatly reducing the production cost, and the prepared EMC has good thermal conductivity. Although thermal conductive fillers such as silica can improve the thermal conductivity of epoxy resin, the poor interface bonding between the epoxy resin and the thermal conductive fillers due to the surface inertness can easily weaken the performance of the prepared epoxy plastic packaging material.

[0005] Therefore, how to improve the interface bonding between the heat-conducting filler and the epoxy resin can not only improve the heat-conducting performance of the epoxy plastic encapsulating material, but also make the epoxy plastic encapsulating material have good mechanical properties. SUMMARY

[0006] According to the deficiencies of the prior art, the heat-conducting epoxy resin plastic encapsulating material is obtained by mixing and curing the polyurethane-coated silicon carbide, the curing agent composition and the epoxy resin composition, thereby solving the technical problems in the background art. Specifically, the technical scheme of the present application includes the following contents:

[0007] One of the purposes of the present application is to provide a preparation method of a heat-conducting epoxy resin plastic encapsulating material for packaging materials, which comprises the following steps:

[0008] The polyurethane-coated silicon carbide, the curing agent composition and the epoxy resin composition are mixed in a weight ratio of 15-21:20-23:30-36, vacuum degassing treatment is performed, and then heated to 90-100 DEG C for 3-4 h to obtain the heat-conducting epoxy resin plastic encapsulating material.

[0009] Further, the preparation method of the polyurethane-coated silicon carbide comprises the following steps:

[0010] The modified silicon carbide, dimethylol propionic acid, EDC hydrochloride and 1-hydroxy benzotriazole are mixed in a weight ratio of 1:10-13:15-18:15-18 and reacted at 25 DEG C for 20-24 h to obtain the dihydroxy-modified silicon carbide;

[0011] The dihydroxy-modified silicon carbide, diisocyanate, polyhydric alcohol and dibutyl tin dilaurate are mixed in a weight ratio of 10:20-30:10-15:0.06-0.07, heated to 80-85 DEG C and reacted for 2-3 h to obtain the polyurethane-coated silicon carbide.

[0012] Further, the preparation method of the modified silicon carbide comprises the following steps:

[0013] The silicon carbide is treated by plasma to obtain pretreated silicon carbide;

[0014] The silane coupling agent, water and anhydrous ethanol are mixed in a weight ratio of 10:60-68:20-28 to obtain a hydrolysis solution by pre-hydrolysis;

[0015] The pretreated silicon carbide and the hydrolysis solution are mixed and dispersed to react to obtain the modified silicon carbide.

[0016] Further, the conditions of the plasma treatment include that the plasma gas source is oxygen, the gas flow is 200-250 mL / min, the treatment power is 150-170 W and the treatment time is 100-120 s.

[0017] Further, the silane coupling agent includes γ-aminopropyltrimethoxysilane or γ-aminopropyltriethoxysilane, which needs to contain amino groups for subsequent introduction of dimethylol propionic acid onto the modified silicon carbide through an amidation reaction, and then dispersing the silicon carbide in polyurethane through a polymerization reaction to achieve polymeric coating of the silicon carbide.

[0018] Further, the mixing pre-hydrolysis conditions include a pre-hydrolysis pH of 4-4.5, a pre-hydrolysis time of 40-50 min, and a pre-hydrolysis temperature of 30-40℃.

[0019] Further, the weight ratio of the pretreated silicon carbide to the silane coupling agent is 5-6:1.

[0020] Further, the mixing and dispersion reaction conditions of the pretreated silicon carbide and the hydrolysis solution include a reaction temperature of 60-70℃ and a reaction time of 80-90 min.

[0021] Further, the diisocyanate includes isophorone diisocyanate.

[0022] Further, the polyhydric alcohol includes polypropylene glycol 1000 or polycaprolactone diol 2000, where polypropylene glycol 1000 refers to polypropylene glycol with a Mn of 1000, and polycaprolactone diol 2000 refers to polycaprolactone diol with a Mn of 2000.

[0023] Further, the curing agent composition is composed of DMP-30 and methyl hexahydrophthalic anhydride in a weight ratio of 1:50.

[0024] Further, the epoxy resin composition is composed of phenol novolac epoxy resin and epoxy resin E-44 in a weight ratio of 1:4.

[0025] Further, the defoaming treatment conditions include a defoaming temperature of 50℃ and a defoaming time of 30-40 min.

[0026] The second object of the present application provides a thermally conductive epoxy resin plastic packaging material prepared by the preparation method of the thermally conductive epoxy resin plastic packaging material for packaging materials.

[0027] Compared with the prior art, the present application has the following advantages:

[0028] The present application firstly utilizes plasma to oxidize and modify the surface of silicon carbide with good heat conduction performance to obtain pretreated silicon carbide. High-energy oxygen atoms, oxygen ions and free radicals in oxygen plasma will bombard the surface of silicon carbide, initiate oxidation reaction, and access oxygen-containing groups such as hydroxyl groups, thereby improving the surface activity of silicon carbide. Then, the pretreated silicon carbide is surface grafted by using a silane coupling agent containing amino groups to obtain modified silicon carbide. Under the activation catalysis of EDC hydrochloride and 1-hydroxybenzotriazole, the modified silicon carbide and dimethylol propionic acid are subjected to amidation condensation reaction of amino and carboxyl ester bond to obtain dihydroxy modified silicon carbide. Under the catalysis of dibutyltin dilaurate, the dihydroxy modified silicon carbide, diisocyanate and polyhydric alcohol realize polymerization and wrapping of silicon carbide, and then polyurethane coated silicon carbide is obtained. The polyurethane coated silicon carbide is crosslinked with epoxy resin to obtain a heat conductive epoxy resin plastic encapsulant. On the one hand, the surface of silicon carbide is grafted and modified to realize polymerization and wrapping of silicon carbide, so that it can be uniformly dispersed in polyurethane, and the interface bonding between silicon carbide and epoxy resin is improved by using the carrier of polyurethane. On the other hand, the flexible long chain of polyurethane can improve the brittle stress after the curing of epoxy resin. Through the synergistic cooperation of silicon carbide and polyurethane, not only the heat conduction performance of the prepared heat conductive epoxy resin plastic encapsulant is realized, but also the mechanical properties are good. DETAILED DESCRIPTION

[0029] The technical solutions of the present application will be described clearly and completely by the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0030] Unless otherwise specified, the raw materials and reagents used in the present application are commercially available or can be prepared by known methods.

[0031] The phenol novolac epoxy resin is purchased from Jinan Shengxing Group Co., Ltd., and the model is SQPN-051.

[0032] Preparation Example 1:

[0033] The preparation method of the modified silicon carbide specifically includes the following processes:

[0034] The silicon carbide powder with a particle size of 0.85 μm is mixed with anhydrous ethanol and placed in an ultrasonic cleaner for cleaning at a power of 300 W for 15 min, and then the silicon carbide is taken out by suction filtration. Deionized water is added and cleaned in the ultrasonic cleaner at a power of 300 W for 15 min, and then vacuum dried until the weight is constant. The cleaned and dried silicon carbide is placed in the reaction chamber of a plasma reactor, and then oxygen is introduced into the reaction chamber to discharge the air in the reaction chamber. The flow rate of oxygen is controlled at 200 mL / min, the power is turned on for discharge, the discharge power is controlled at 150 W, the discharge phenomenon occurs in the reaction chamber, and then the timing process is started for 100 s. The pretreated silicon carbide obtained after the process is stored at room temperature under vacuum for use;

[0035] 60 parts by weight of deionized water and 20 parts by weight of anhydrous ethanol are weighed and mixed and stirred uniformly, and then 10 parts by weight of γ-aminopropyltrimethoxysilane is added and mixed and stirred until it is uniformly dispersed. The pH value of the uniformly dispersed dispersion liquid is adjusted to 4 with dilute hydrochloric acid, and the hydrolysis liquid is obtained by pre-hydrolysis treatment in a water bath at 30°C for 40 min. 50 parts by weight of pretreated silicon carbide is added to the hydrolysis liquid and dispersed by ultrasonic power of 400 W for 10 min. After uniform dispersion, heating is carried out to 60°C for timed reaction for 80 min. After the reaction is completed, suction filtration is carried out, and then washing is carried out with anhydrous ethanol and deionized water. Finally, drying treatment is carried out in a drying oven at 50°C for 6 h, and then the modified silicon carbide is obtained after cooling to room temperature. The modified silicon carbide is sealed and stored for use.

[0036] Preparation Example 2:

[0037] The preparation method of the modified silicon carbide specifically includes the following processes:

[0038] The silicon carbide powder with a particle size of 0.85 μm is mixed with anhydrous ethanol and placed in an ultrasonic cleaner for cleaning at a power of 300 W for 15 min, and then the silicon carbide is taken out by suction filtration. Deionized water is added and cleaned in the ultrasonic cleaner at a power of 300 W for 15 min, and then vacuum dried until the weight is constant. The cleaned and dried silicon carbide is placed in the reaction chamber of a plasma reactor, and then oxygen is introduced into the reaction chamber to discharge the air in the reaction chamber. The flow rate of oxygen is controlled at 200 mL / min, the power is turned on for discharge, the discharge power is controlled at 150 W, the discharge phenomenon occurs in the reaction chamber, and then the timing process is started for 100 s. The pretreated silicon carbide obtained after the process is stored at room temperature under vacuum for use;

[0039] Take 64 parts by weight of deionized water and 24 parts by weight of anhydrous ethanol, mix and stir uniformly, then add 10 parts by weight of γ-aminopropyltrimethoxysilane and mix and stir until dispersed uniformly, adjust the pH value of the dispersed solution after dispersion to 4.5 with dilute hydrochloric acid, and place it in a 35℃ water bath for pre-hydrolysis treatment for 45min to obtain a hydrolysis solution; add 55 parts by weight of pre-treated silicon carbide to the hydrolysis solution and disperse for 10min under an ultrasonic power of 400W. After uniform dispersion, heat to 65℃ and react for 85min. After the reaction is completed, filter, wash with anhydrous ethanol, then wash with deionized water, and finally dry in a drying oven at 50℃ for 6h, cool to room temperature to obtain modified silicon carbide, and seal for storage until use.

[0040] Preparation Example 3:

[0041] The preparation method of the modified silicon carbide specifically includes the following processes:

[0042] The silicon carbide powder with a particle size of 0.85μm is mixed with anhydrous ethanol and placed in an ultrasonic cleaner for cleaning at a power of 300W for 15min, then the silicon carbide is taken out by suction filtration, deionized water is added and cleaned in an ultrasonic cleaner at a power of 300W for 15min, and then vacuum dried until the weight is constant. The cleaned and dried silicon carbide is placed in the reaction chamber of a plasma reactor, then oxygen is introduced into the reaction chamber to remove the air in the reaction chamber, the flow rate of oxygen is controlled at 250mL / min, the power is turned on to discharge, the discharge power is controlled at 170W, and the discharge phenomenon occurs in the reaction chamber, then the timing treatment is started for 120s. The pretreated silicon carbide obtained after the treatment is stored at room temperature under vacuum until use;

[0043] Take 68 parts by weight of deionized water and 28 parts by weight of anhydrous ethanol, mix and stir uniformly, then add 10 parts by weight of γ-aminopropyltriethoxysilane and mix and stir until dispersed uniformly, adjust the pH value of the dispersed solution after dispersion to 4.5 with dilute hydrochloric acid, and place it in a 40℃ water bath for pre-hydrolysis treatment for 50min to obtain a hydrolysis solution; add 60 parts by weight of pre-treated silicon carbide to the hydrolysis solution and disperse for 10min under an ultrasonic power of 400W. After uniform dispersion, heat to 70℃ and react for 90min. After the reaction is completed, filter, wash with anhydrous ethanol, then wash with deionized water, and finally dry in a drying oven at 50℃ for 6h, cool to room temperature to obtain modified silicon carbide, and seal for storage until use.

[0044] Preparation Example 4:

[0045] The preparation method of the modified silicon carbide specifically includes the following processes:

[0046] In preparation example 3, γ-aminopropyltriethoxysilane is replaced by silane coupling agent KH560, and the rest of the preparation process is the same as that of preparation example 3.

[0047] Preparation Example 5:

[0048] The preparation method of the modified silicon carbide specifically includes the following processes:

[0049] The 68 parts by weight of deionized water and 28 parts by weight of anhydrous ethanol are mixed and stirred uniformly, then 10 parts by weight of γ-aminopropyl triethoxysilane is added and mixed and stirred until uniformly dispersed, the pH value of the uniformly dispersed dispersion liquid is adjusted to 4.5 with dilute hydrochloric acid, and the dispersion liquid is placed in a water bath at 50°C for pre-hydrolysis treatment for 80 min to obtain a hydrolysis liquid; 60 parts by weight of the pretreated silicon carbide obtained in Preparation Example 3 is added to the hydrolysis liquid and dispersed by ultrasonic power of 400 W for 10 min. After uniform dispersion, heating is performed to 70°C for timed reaction for 90 min. After the reaction is completed, filtration is performed, washing is performed with anhydrous ethanol, then washing is performed with deionized water, and finally drying treatment is performed in a drying oven at 50°C for 6 h, and cooling is performed to room temperature to obtain the modified silicon carbide, which is sealed and stored for use.

[0050] Preparation Example 6:

[0051] The preparation method of the modified silicon carbide specifically includes the following processes:

[0052] The 0.85 μm silicon carbide powder in Preparation Example 3 is replaced with 0.3 μm silicon carbide powder, and the rest of the preparation process is consistent with Preparation Example 3.

[0053] Preparation Example 7:

[0054] The preparation method of the polyurethane-coated silicon carbide specifically includes the following processes:

[0055] 10 parts by weight of dimethylol propionic acid, 15 parts by weight of EDC hydrochloride, and 15 parts by weight of 1-hydroxybenzotriazole are mixed and placed in a flask, 100 parts by weight of anhydrous dichloromethane is added to form a reaction system, the temperature of the reaction system is controlled at 0°C for pre-treatment for 15 min (10 parts by weight of triethylamine can be appropriately added to improve the pre-treatment effect), then 1 part by weight of the modified silicon carbide obtained in Preparation Example 1 is added, stirring and mixing are performed at a rotation speed of 400 r / min, and the temperature is increased to 25°C, and stirring and reaction are performed at this temperature for 20 h. After the reaction is completed, solid particles are obtained by filtration, the solid particles are washed with saturated sodium carbonate solution, then washed with deionized water, then dried under reduced pressure to obtain the dihydroxy-modified silicon carbide;

[0056] After the isophorone diisocyanate and the polypropylene glycol 1000 are dried and dehydrated, 10 parts by weight of the dihydroxy-modified silicon carbide, 20 parts by weight of the isophorone diisocyanate, 10 parts by weight of the polypropylene glycol 1000, and 0.06 parts by weight of dibutyltin dilaurate are added to a reactor, then heating is performed to 80°C for reaction for 2 h to obtain the polyurethane-coated silicon nitride.

[0057] Preparation Example 8:

[0058] The preparation method of the polyurethane coated silicon carbide specifically includes the following processes:

[0059] Take 12 parts by weight of dimethylol propionic acid, 16 parts by weight of EDC hydrochloride and 16 parts by weight of 1-hydroxybenzotriazole, mix and place them in a flask, then add 100 parts by weight of anhydrous dichloromethane to form a reaction system, control the temperature of the reaction system at 0°C for pretreatment for 15 min (10 parts by weight of triethylamine can be appropriately added to improve the pretreatment effect). Then add 1 part by weight of the modified silicon carbide obtained in Preparation Example 2, stir and mix at a speed of 400 r / min and warm up to 25°C, and stir and react at this temperature for 22 h. After the reaction is completed, the solid particles are obtained by suction filtration, the solid particles are washed with saturated sodium carbonate solution, then washed with deionized water, and then dried under reduced pressure to obtain the dihydroxy modified silicon carbide;

[0060] After drying and dehydrating isophorone diisocyanate and polypropylene glycol 1000, take 10 parts by weight of dihydroxy modified silicon carbide, 25 parts by weight of isophorone diisocyanate, 13 parts by weight of polypropylene glycol 1000 and 0.065 parts by weight of dibutyltin dilaurate, and then heat to 80°C for 2.5 h to obtain the polyurethane coated silicon nitride.

[0061] Preparation Example 9:

[0062] The preparation method of the polyurethane coated silicon carbide specifically includes the following processes:

[0063] Take 13 parts by weight of dimethylol propionic acid, 18 parts by weight of EDC hydrochloride and 18 parts by weight of 1-hydroxybenzotriazole, mix and place them in a flask, then add 100 parts by weight of anhydrous dichloromethane to form a reaction system, control the temperature of the reaction system at 0°C for pretreatment for 15 min (10 parts by weight of triethylamine can be appropriately added to improve the pretreatment effect). Then add 1 part by weight of the modified silicon carbide obtained in Preparation Example 2, stir and mix at a speed of 400 r / min and warm up to 25°C, and stir and react at this temperature for 22 h. After the reaction is completed, the solid particles are obtained by suction filtration, the solid particles are washed with saturated sodium carbonate solution, then washed with deionized water, and then dried under reduced pressure to obtain the dihydroxy modified silicon carbide;

[0064] After drying and dehydrating isophorone diisocyanate and polycaprolactone diol 2000, take 10 parts by weight of dihydroxy modified silicon carbide, 30 parts by weight of isophorone diisocyanate, 15 parts by weight of polycaprolactone diol 2000 and 0.07 parts by weight of dibutyltin dilaurate, and then heat to 85°C for 3 h to obtain the polyurethane coated silicon nitride.

[0065] Preparation Example 10:

[0066] A method for preparing polyurethane-coated silicon carbide, specifically comprising the following processes:

[0067] The modified silicon carbide in Preparation Example 9 is replaced with the modified silicon carbide obtained in Preparation Example 4, and the rest of the preparation process remains the same as that in Preparation Example 9.

[0068] Preparation Example 11:

[0069] A method for preparing polyurethane-coated silicon carbide, specifically comprising the following processes:

[0070] The modified silicon carbide in Preparation Example 9 is replaced with the modified silicon carbide obtained in Preparation Example 5, and the rest of the preparation process remains the same as that in Preparation Example 9.

[0071] Preparation Example 12:

[0072] A method for preparing polyurethane-coated silicon carbide, specifically comprising the following processes:

[0073] The modified silicon carbide in Preparation Example 9 is replaced with the modified silicon carbide obtained in Preparation Example 6, and the rest of the preparation process remains the same as that in Preparation Example 9.

[0074] Preparation Example 13:

[0075] A method for preparing polyurethane-coated silicon carbide, specifically comprising the following processes:

[0076] The modified silicon carbide in Preparation Example 9 is replaced with the pretreated silicon carbide obtained in Preparation Example 6, and the rest of the preparation process remains the same as that in Preparation Example 9.

[0077] Example 1:

[0078] A method for preparing a heat-conducting epoxy resin plastic packaging material for packaging materials, specifically comprising the following processes:

[0079] After mixing 15 parts by weight of the polyurethane-coated silicon carbide obtained in Preparation Example 7, 20 parts by weight of a curing agent composition (consisting of DMP-30 and methylhexahydrophthalic anhydride in a weight ratio of 1:50), and 30 parts by weight of an epoxy resin composition (consisting of a phenol novolac epoxy resin with model number SQPN-051 and an epoxy resin E-44 in a weight ratio of 1:4), heat to 50°C, then vacuum degassing for 30 min, and then heat to 90°C for 3h to obtain a heat-conducting epoxy resin plastic packaging material.

[0080] Example 2:

[0081] A method for preparing a heat-conducting epoxy resin plastic packaging material for packaging materials, specifically comprising the following processes:

[0082] A heat conductive epoxy resin plastic encapsulant for packaging material is prepared by mixing 18 parts by weight of the polyurethane-coated silicon carbide obtained in Preparation Example 8, 21 parts by weight of a curing agent composition (consisting of DMP-30 and methyl hexahydrophthalic anhydride in a weight ratio of 1:50), and 33 parts by weight of an epoxy resin composition (consisting of a phenol novolac epoxy resin of model SQPN-051 and an epoxy resin E-44 in a weight ratio of 1:4), heating to 50°C, vacuum degassing for 35 minutes, and then heating to 95°C and curing for 3.5 hours.

[0083] Example 3:

[0084] A method for preparing a heat conductive epoxy resin plastic encapsulant for packaging material, specifically comprising the following processes:

[0085] A heat conductive epoxy resin plastic encapsulant for packaging material is prepared by mixing 21 parts by weight of the polyurethane-coated silicon carbide obtained in Preparation Example 9, 23 parts by weight of a curing agent composition (consisting of DMP-30 and methyl hexahydrophthalic anhydride in a weight ratio of 1:50), and 36 parts by weight of an epoxy resin composition (consisting of a phenol novolac epoxy resin of model SQPN-051 and an epoxy resin E-44 in a weight ratio of 1:4), heating to 50°C, vacuum degassing for 40 minutes, and then heating to 100°C and curing for 3 hours.

[0086] Comparative Example 1:

[0087] A method for preparing a heat conductive epoxy resin plastic encapsulant for packaging material, specifically comprising the following processes:

[0088] The polyurethane-coated silicon carbide in Example 3 is replaced with the polyurethane-coated silicon carbide obtained in Preparation Example 10, and the rest of the preparation process is consistent with Example 3.

[0089] Comparative Example 2:

[0090] A method for preparing a heat conductive epoxy resin plastic encapsulant for packaging material, specifically comprising the following processes:

[0091] The polyurethane-coated silicon carbide in Example 3 is replaced with the polyurethane-coated silicon carbide obtained in Preparation Example 11, and the rest of the preparation process is consistent with Example 3.

[0092] Comparative Example 3:

[0093] A method for preparing a heat conductive epoxy resin plastic encapsulant for packaging material, specifically comprising the following processes:

[0094] The polyurethane-coated silicon carbide in Example 3 is replaced with the polyurethane-coated silicon carbide obtained in Preparation Example 12, and the rest of the preparation process is consistent with Example 3.

[0095] Comparative Example 4:

[0096] A preparation method of a heat conductive epoxy resin plastic encapsulating material for packaging materials, specifically comprising the following processes:

[0097] The polyurethane-coated silicon carbide in Example 3 is replaced with the polyurethane-coated silicon carbide obtained in Preparation Example 13, and the rest of the preparation process remains the same as in Example 3.

[0098] Comparative Example 5:

[0099] A preparation method of a heat conductive epoxy resin plastic encapsulating material for packaging materials, specifically comprising the following processes:

[0100] 21 parts by weight of the polyurethane-coated silicon carbide obtained in Preparation Example 9, 23 parts by weight of a curing agent composition (consisting of DMP-30 and methylhexahydrophthalic anhydride in a weight ratio of 10:40), and 36 parts by weight of an epoxy resin composition (consisting of a phenol novolac epoxy resin with model number SQPN-051 and an epoxy resin E-44 in a weight ratio of 1:4) are mixed and heated to 50°C, followed by vacuum degassing treatment for 40 min, and then heated to 100°C for curing for 3 h to obtain a heat conductive epoxy resin plastic encapsulating material.

[0101] Comparative Example 6:

[0102] A preparation method of a heat conductive epoxy resin plastic encapsulating material for packaging materials, specifically comprising the following processes:

[0103] The polyurethane-coated silicon carbide in Example 3 is replaced with the modified silicon carbide obtained in Preparation Example 3, and the rest of the preparation process remains the same as in Example 3.

[0104] According to GB / T 29313-2012, the thermal conductivity of the heat conductive epoxy resin plastic encapsulating materials obtained in Examples 1-3 and Comparative Examples 1-5 is tested, and the results are shown in Table 1 below.

[0105] Table 1 Thermal conductivity

[0106]

[0107] According to GB / T 1843-2008, the impact strength of the heat conductive epoxy resin plastic encapsulating materials obtained in Examples 1-3 and Comparative Examples 1-5 is tested, and the sample size is a sample bar with dimensions of 80mm x 10mm x 4mm, and the notch is 2mm. The results are shown in Table 2 below.

[0108] Table 2 Impact strength

[0109]

[0110] The following conclusions can be drawn from the test results of Table 1 and Table 2 above:

[0111] (1) It can be found from Examples 1-3 that the heat-conducting epoxy resin plastic encapsulating material prepared by mixing and curing the polyurethane-coated silicon carbide, the curing agent composition and the epoxy resin composition has good heat-conducting performance and mechanical properties.

[0112] (2) It can be found from Comparative Example 1 that the heat-conducting performance and mechanical properties of the prepared heat-conducting epoxy resin plastic encapsulating material are poor, which may be because the silane coupling agent KH560 lacks the reactive amino group compared to γ-aminopropyl triethoxysilane, and is difficult to be coated by polyurethane polymerization, thereby making it difficult to improve the interfacial bonding between silicon carbide and epoxy resin, and finally the performance is poor.

[0113] (3) It can be found from Comparative Example 2 that the heat-conducting performance and mechanical properties of the prepared heat-conducting epoxy resin plastic encapsulating material are poor, which may be because the hydrolysis time of γ-aminopropyl triethoxysilane is too long, which is easy to form polysiloxane structure by self-polymerization, resulting in difficulty in modification of silicon carbide, and finally the performance of the prepared heat-conducting epoxy resin plastic encapsulating material is poor.

[0114] (4) It can be found from Comparative Example 3 that the heat-conducting performance and mechanical properties of the prepared heat-conducting epoxy resin plastic encapsulating material are poor, which may be because in this system, the further treatment of silicon carbide with small particle size has poor treatment effect by plasma, resulting in poor pretreatment effect on the surface of silicon carbide, and thus the performance of the prepared heat-conducting epoxy resin plastic encapsulating material is poor.

[0115] (5) It can be found from Comparative Example 4 that the heat-conducting performance and mechanical properties of the prepared heat-conducting epoxy resin plastic encapsulating material are poor, which may be because in this system, the pretreated silicon carbide obtained by plasma oxidation has an active surface with oxygen-containing groups such as hydroxyl groups, but if it is not further dispersed, the agglomeration phenomenon may still be obvious, which affects the uniform dispersion performance in the polymerization reaction, and thus affects the preparation of polyurethane-coated silicon carbide, resulting in poor performance of the prepared heat-conducting epoxy resin plastic encapsulating material.

[0116] (6) It can be found from Comparative Example 5 that the heat-conducting performance and mechanical properties of the prepared heat-conducting epoxy resin plastic encapsulating material are poor, which may be because in this system, if the amount of DMP-30 as a curing accelerator in the curing agent composition is too much, it may cause the surface to be cured too quickly, while the inner layer is not fully cross-linked and cured, the resin matrix is damaged, and finally the performance of the prepared heat-conducting epoxy resin plastic encapsulating material is poor.

[0117] (7) It can be found from Comparative Example 6 that the prepared heat-conducting epoxy resin plastic encapsulating material has poor heat-conducting performance and mechanical properties, which is probably because in the system, the modified silicon carbide is directly used without the coating treatment of polyurethane, and the brittle stress of the resin matrix is too high, resulting in poor performance of the prepared heat-conducting epoxy resin plastic encapsulating material.

[0118] The above embodiments describe the technical solutions and beneficial effects of the present application in detail. It should be understood that the above description is only a specific embodiment of the present application and is not intended to limit the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application.

Claims

1. A method for preparing a thermally conductive epoxy resin plastic encapsulant for encapsulating materials, characterized in that, The preparation method comprises the following steps: The polyurethane coated silicon carbide, the curing agent composition and the epoxy resin composition are mixed in a weight ratio of 15-21:20-23:30-36, vacuum degassing treatment, and then heated to 90-100 DEG C for 3-4 h to obtain the heat conductive epoxy resin plastic packaging material; The preparation method of the polyurethane coated silicon carbide comprises the following steps: The modified silicon carbide, dimethylol propionic acid, EDC hydrochloride and 1-hydroxy benzotriazole are mixed in a weight ratio of 1:10-13:15-18:15-18 and reacted at 25 DEG C for 20-24 h to obtain the dihydroxy modified silicon carbide; The dihydroxy modified silicon carbide, diisocyanate, polyhydric alcohol and dibutyl tin dilaurate are mixed in a weight ratio of 10:20-30:10-15:0.06-0.07, heated to 80-85 DEG C and reacted for 2-3 h to obtain the polyurethane coated silicon carbide; The preparation method of the modified silicon carbide comprises the following steps: The silicon carbide is treated by plasma to obtain pretreated silicon carbide; The silane coupling agent, water and anhydrous ethanol are mixed to obtain a hydrolysis solution; The pretreated silicon carbide and the hydrolysis solution are mixed and dispersed to obtain the modified silicon carbide; The particle size of the silicon carbide is 0.85 μm; The silane coupling agent is γ-aminopropyl trimethoxysilane or γ-aminopropyl triethoxysilane; The conditions of the mixing and pre-hydrolysis include that the pre-hydrolysis pH is 4-4.5, the pre-hydrolysis time is 40-50 min and the pre-hydrolysis temperature is 30-40 DEG C; The curing agent composition is composed of DMP-30 and methyl hexahydrophthalic anhydride in a weight ratio of 1:

50.

2. The method of claim 1, wherein the thermally conductive epoxy molding compound is prepared by mixing the thermally conductive filler with the epoxy resin, the curing agent, the curing catalyst, and the solvent. The conditions of the plasma treatment include that the plasma gas source is oxygen, the gas flow is 200-250 mL / min, the treatment power is 150-170 W and the treatment time is 100-120 s.

3. The method of claim 1, wherein the thermally conductive epoxy molding compound is prepared by mixing the thermally conductive filler, the epoxy resin, the curing agent, the curing catalyst, and the diluent. The weight ratio of the pretreated silicon carbide to the silane coupling agent is 5-6:

1.

4. The method of claim 1, wherein the thermally conductive epoxy molding compound is prepared by mixing the thermally conductive filler, the epoxy resin, the curing agent, the curing catalyst, and the diluent. The conditions of the mixing and pre-hydrolysis include that the pre-hydrolysis pH is 4-4.5, the pre-hydrolysis time is 40-50 min and the pre-hydrolysis temperature is 30-40 DEG C; 5. The method of claim 1, wherein the thermally conductive epoxy molding compound is prepared by mixing the thermally conductive filler, the epoxy resin, the curing agent, the curing catalyst, and the diluent. The epoxy resin composition is composed of phenol novolac epoxy resin and epoxy resin E-44 in a weight ratio of 1:

4. 6.A heat conductive epoxy resin plastic packaging material prepared by the preparation method of claim 1-5.

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