High-thermal-conductivity epoxy plastic packaging material, preparation method and application thereof

Abstract

The application provides a high-thermal-conductivity epoxy plastic packaging material and a preparation method and application thereof, and belongs to the technical field of electronic packaging materials.The high-thermal-conductivity epoxy plastic packaging material comprises the following components: an epoxy resin, a phenolic resin, a filler, a curing accelerator, a silane coupling agent, a stress release agent, a colorant, a flame retardant and fumed silicon, and the epoxy resin is an epoxy resin for packaging and / or a liquid crystal type epoxy resin.The liquid crystal type epoxy resin and spherical alumina filler are selected to improve the thermal conductivity of the epoxy plastic packaging material and keep good continuous formability, and the stress release agent is selected to reduce the modulus and take into account the reliability, so that the epoxy plastic packaging material has good reliability and continuous formability while having high thermal conductivity.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electronic packaging materials, in particular to a high-thermal-conductivity epoxy plastic packaging material and a preparation method and application thereof. BACKGROUND

[0002] To cope with the global energy resource crisis, the world energy saving, global energy revolution drives new energy vehicles, photovoltaic, wind power and other downstream application fields, power equipment (power semiconductor) is highly valued. At the same time, the 5G era needs higher voltage, higher frequency and high power components. Therefore, the research and development of high conversion efficiency compound semiconductors such as silicon carbide (SiC) and gallium nitride (GaN) has become a new competitive research and development direction. Compared with traditional Si components, SiC and GaN components have the characteristics of high voltage resistance and high working temperature, so higher requirements are put forward for the thermal conductivity of epoxy plastic packaging materials.

[0003] In order to ensure the high thermal conductivity of the epoxy plastic packaging material, the current common strategy is to increase the filling fraction of the filler, but high filling fraction inevitably affects the continuous forming property of the plastic packaging material and the modulus of the plastic packaging material. Therefore, it is urgent to develop intrinsic high-thermal-conductivity epoxy resin and apply it to the development of epoxy plastic packaging materials, so as to have high thermal conductivity and good processability to meet the application requirements. SUMMARY

[0004] Therefore, the present application provides a high-thermal-conductivity epoxy plastic packaging material and a preparation method and application thereof, which selects an epoxy resin and / or a liquid crystal type epoxy resin as a resin system component and selects alumina and / or silicon oxide as a filler component. The epoxy plastic packaging material has high thermal conductivity and good continuous forming property.

[0005] The present application provides a high-thermal-conductivity epoxy plastic packaging material, which comprises the following components: an epoxy resin, a phenolic resin, a filler, a curing accelerator, a silane coupling agent, a stress release agent, a colorant, a flame retardant and fumed silicon.

[0006] The mass of the epoxy resin is 4% to 25% of the mass of the plastic packaging material, the mass of the phenolic resin is 3% to 15% of the mass of the plastic packaging material, the mass of the filler is 60% to 93% of the mass of the plastic packaging material, the mass of the curing accelerator is 0.05% to 2% of the mass of the plastic packaging material, the mass of the silane coupling agent is 0.05% to 5% of the mass of the filler, the mass of the stress release agent is 0.5% to 5% of the mass of the filler, the mass of the release agent is 0.005% to 2% of the mass of the plastic packaging material, the mass of the colorant is 0.1% to 0.6% of the mass of the plastic packaging material, the mass of the flame retardant is 0.1% to 0.5% of the mass of the plastic packaging material, and the mass of the fumed silicon is 0.1% to 0.5% of the mass of the plastic packaging material.

[0007] Preferably, the epoxy resin is an encapsulating epoxy resin and / or a liquid crystal type epoxy resin.

[0008] The encapsulating epoxy resin includes at least one of a phenol novolac type epoxy resin, an o-cresol novolac type epoxy resin, an alkyl-substituted or non-substituted diglycidyl ether type epoxy resin, a 1,2-diphenylstyrene type epoxy resin, an epoxy resin containing a sulfur atom, a hydroquinone type epoxy resin, a glycidyl ester type epoxy resin, a glycidyl amine type epoxy resin, an epoxide of a dicyclopentadiene co-condensation resin with phenols and / or naphthols, an epoxy resin containing a naphthalene ring, a phenol aralkyl resin, an epoxide of an aralkyl phenol resin, a trimethylolpropane type epoxy resin, and an ester cyclic epoxy resin.

[0009] The liquid crystal type epoxy resin is at least one of the epoxy resins of the following chemical structural formulas 2-1, 2-2, 2-3, 2-4, 2-5, and 2-6:

[0010]

[0011]

[0012] Preferably, the encapsulating epoxy resin is at least one of the epoxy resins of the following chemical structural general formulas 1-1 and 1-2:

[0013]

[0014] wherein each R is independently selected from a hydrogen atom, or a substituted or unsubstituted monovalent hydrocarbon group having m carbon atoms, m being an integer of any value from 0 to 10; n is independently an integer of any value from 0 to 3.

[0015] Preferably, the mass of the liquid crystal type epoxy resin accounts for 5% to 100% of the mass of the epoxy resin.

[0016] Preferably, the ratio of the total number of epoxy groups in the epoxy resin to the total number of hydroxyl groups in the phenolic resin, i.e., the equivalent ratio, is 0.5 to 2.

[0017] Preferably, the filler is an inorganic filler, and the inorganic filler is at least one of crystalline silica, fused silica, synthetic silica, aluminum oxide, aluminum nitride, boron nitride, zircon, calcium silicate, calcium carbonate, and barium titanate; the average particle size of the inorganic filler is 0.1 to 53 μm.

[0018] Preferably, the phenolic resin is at least one of a phenol novolac resin, a biphenyl aralkyl type phenolic resin, a cresol novolac type epoxy resin, a biphenyl type novolac resin, a triphenylmethane type phenolic resin, a naphthol novolac resin, and an aralkyl phenolic resin.

[0019] The curing accelerator is at least one of a cyclic amidine compound and / or a quinone compound added thereto, an imidazoline compound and / or its derivative, an organic phosphine and / or a compound having a π-bond and intramolecular polarity added thereto;

[0020] The chemical structure formula 3 of the silane coupling agent is:

[0021]

[0022] Wherein, m is an integer ranging from 1 to 3; n is an integer ranging from 0 to 3; R 1 Selected from

[0023] Any one of the following, j is selected from a hydrogen atom, or an alkyl group with any carbon number of 1 to 6; R 2 and R 3 are each independently selected from methyl or ethyl, and in R 2 and R 3 When there are multiple, they may be the same or different from each other;

[0024] The stress release agent is an organic silicon compound; the release agent is a linear saturated carboxylic acid and / or oxidized polyethylene wax, wherein the number average molecular weight of the oxidized polyethylene wax is 550-1200; the colorant is a carbon black agent; the flame retardant is an ester of phosphoric acid and alcohol or phenol; and the fumed silicon is fumed silicon dioxide with an average particle size of 5 to 40 nm.

[0025] Preferably, it also includes an ion capture agent and / or other auxiliary agents.

[0026] The present invention also provides a method for preparing the high thermal conductivity epoxy molding compound as described above, comprising the following steps:

[0027] The components are weighed in proportion, and then kneaded and mixed at an extrusion temperature of 100-140° C., cooled, and finely pulverized to obtain the epoxy molding compound.

[0028] The present invention also provides a use of the above-mentioned high thermal conductivity epoxy molding compound in semiconductor packaging.

[0029] The high thermal conductivity epoxy molding compound of the present invention has the following beneficial effects compared with the prior art:

[0030] The conventional resin system epoxy plastic encapsulating material cannot meet the high thermal conductivity while considering the reliability and good process formability. The high thermal conductivity epoxy plastic encapsulating material of the application selects liquid crystal type epoxy resin and spherical alumina filler to improve the thermal conductivity of the epoxy plastic encapsulating material and keep good continuous formability, selects stress release agent to reduce modulus, and considers reliability, so as to realize the good reliability and continuous formability of the epoxy plastic encapsulating material while having high thermal conductivity. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the application will be clearly and completely described below in combination with the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the application.

[0032] The application provides a high thermal conductivity epoxy plastic encapsulating material, which comprises the following components: epoxy resin, phenolic resin, filler, curing accelerator, silane coupling agent, stress release agent, colorant, flame retardant and fumed silica.

[0033] The mass of the epoxy resin is 4% to 25% of the mass of the plastic encapsulating material, the mass of the phenolic resin is 3% to 15% of the mass of the plastic encapsulating material, the mass of the filler is 60% to 93% of the mass of the plastic encapsulating material, the mass of the curing accelerator is 0.05% to 2% of the mass of the plastic encapsulating material, the mass of the silane coupling agent is 0.05% to 5% of the mass of the filler, the mass of the stress release agent is 0.5% to 5% of the mass of the filler, the mass of the release agent is 0.005% to 2% of the mass of the plastic encapsulating material, the mass of the colorant is 0.1% to 0.6% of the mass of the plastic encapsulating material, the mass of the flame retardant is 0.1% to 0.5% of the mass of the plastic encapsulating material, and the mass of the fumed silica is 0.1% to 0.5% of the mass of the plastic encapsulating material.

[0034] The epoxy resin is encapsulating epoxy resin and / or liquid crystal type epoxy resin, the mass of the liquid crystal type epoxy resin accounts for 5% to 100% of the mass of the epoxy resin, preferably 20% to 80%, and more preferably 30% to 70%; when the epoxy resin contains liquid crystal type epoxy resin, the content of the liquid crystal type epoxy resin is 0.5% to 6.5% of the weight of the plastic encapsulating material.

[0035] The encapsulating epoxy resin is not particularly limited and includes, for example, a product obtained by epoxidizing a phenol-formaldehyde resin obtained by condensing or co-condensing a phenol such as phenol, o-cresol, m-cresol, p-cresol, resorcinol, catechol, bisphenol A, bisphenol F, and / or an a- or β-naphthol, a dihydroxynaphthalene, and an aldehyde group-containing compound such as formaldehyde, acetaldehyde, propionaldehyde, benzaldehyde, or salicylaldehyde in the presence of an acid catalyst; an alkyl-substituted or unsubstituted diglycidyl ether-type epoxy resin; a 1,2-stilbene-type epoxy resin; an epoxy resin containing a sulfur atom; a hydroquinone-type epoxy resin; a glycidyl ester-type epoxy resin obtained by reacting a polybasic acid such as phthalic acid or dimer acid with an epichlorohydrin; a glycidyl amine-type epoxy resin obtained by reacting a polyamine such as diaminodiphenylmethane or isocyanic acid with an epichlorohydrin; an epoxide of a co-condensation resin of dicyclopentadiene with a phenol and / or a naphthol; a naphthalene ring-containing epoxy resin; a phenol aralkyl resin; an epoxide of an aralkyl-type phenol resin such as a phenol aralkyl resin or a naphthol aralkyl resin; a trimethylolpropane-type epoxy resin; an ester alicyclic epoxy resin; or the like. These can be used alone or in combination of two or more.

[0036] Preferably, the encapsulating epoxy resin is at least one of the epoxy resins of the following chemical structures General Formula 1-1 and Formula 1-2; when used in combination of the epoxy resins of the chemical structures General Formula 1-1 and Formula 1-2, a desired high thermal conductivity can be obtained, and better flowability is also considered.

[0037]

[0038] wherein each R is independently selected from a hydrogen atom, or a substituted or unsubstituted monovalent hydrocarbon group having m carbon atoms, m being an integer of any value from 0 to 10; and n is independently an integer of any value from 0 to 3.

[0039] The liquid crystal-type epoxy resin is at least one of the epoxy resins of the following chemical structures Formula 2-1, Formula 2-2, Formula 2-3, Formula 2-4, Formula 2-5, and Formula 2-6;

[0040]

[0041] The phenol-formaldehyde resin includes one or more of a phenol novolac resin, a biphenyl aralkyl-type phenol-formaldehyde resin, a cresol novolac-type epoxy resin, a biphenyl-type phenol novolac resin, a triphenylmethane-type phenol-formaldehyde resin, a naphthol novolac resin, and an aralkyl phenol-formaldehyde resin; preferably, the phenol-formaldehyde resin includes one or both of a biphenyl aralkyl-type phenol-formaldehyde resin and a phenol novolac resin.

[0042] The equivalent ratio of the epoxy resin to the phenol resin, i.e., the total number of epoxy groups in the epoxy resin / the total number of hydroxyl groups in the phenol resin, is not particularly limited, and is preferably set in the range of 0.5 to 2, more preferably in the range of 0.6 to 1.3, in order to suppress the respective unreacted portions less. In order to obtain an epoxy resin molding compound for encapsulation having excellent moldability and reflow resistance, it is more preferable to set in the range of 0.8 to 1.0.

[0043] The filler is an inorganic filler, which is at least one of crystalline silica, fused silica, synthetic silica, alumina, aluminum nitride, boron nitride, zircon, calcium silicate, calcium carbonate, and barium titanate. From the viewpoint of flowability and high thermal conductivity, spherical alumina or a mixture of spherical alumina and fused spherical silica can be the main component. The average particle diameter of the inorganic filler is preferably in the range of 0.1 to 53 μm, and more preferably in the range of 0.1 to 40 μm, from the viewpoint of flowability. If the content of the inorganic filler is too small, the viscosity of the epoxy molding compound is too low, and voids are easily generated during molding, and the dielectric constant and the coefficient of thermal expansion are less improved. On the other hand, if the content of the inorganic filler is too large, the flowability of the epoxy molding compound is poor, and defects such as incomplete filling are easily generated. The mass of the inorganic filler is preferably in the range of 70% to 92% of the mass of the molding compound.

[0044] A curing accelerator is required for the hardenability of the epoxy molding compound, and is not particularly limited, and is generally used in an epoxy resin molding compound for encapsulation. The mass of the curing accelerator is preferably in the range of 0.05% to 2% of the mass of the molding compound. If the amount of the curing accelerator is less than 0.05%, the hardenability tends to be poor in a short time. If the amount of the curing accelerator is more than 2%, the hardening speed is too fast, and it is difficult to obtain a molded product having a good shape. The mass of the curing accelerator is preferably in the range of 0.1% to 0.5% of the mass of the molding compound.

[0045] The curing accelerator includes cyclic amidine compounds such as 1,8-diaza- bicyclo[5.4.0]undecene-7, 1,5-diaza-bicyclo[4.3.0]nonene, 5,6-dibutylamino-1,8-diaza- bicyclo[5.4.0]undecene-7, and the like, and quinone compounds such as maleic anhydride, 1,4-benzoquinone, 2,5-toluquinone, 2,3-dimethylbenzoquinone, 2,6-dimethylbenzoquinone, 2,3-dimethoxy-5-methyl-1, and the like, added to these compounds, imidazolines such as 2-methylimidazoline, 2-phenylimidazoline, 2-phenyl-4-methylimidazoline, and the like, and derivatives thereof, organic phosphines such as tributylphosphine, methyldiphenylphosphine, triphenylphosphine, tri(4-methylphenyl)phosphine, diphenylphosphine, phenylphosphine, and the like, and compounds having an intramolecular polarity formed by adding maleic anhydride, the above-mentioned quinone compounds, benzopinacol, phenol resin, and the like, to these phosphines. When an organic phosphine-based curing accelerator is used, the organic phosphine-based curing accelerator is present in a content of 0.05% to 0.6% by weight of the encapsulant.

[0046] The silane coupling agent is present in a content of 0.05% to 0.5% by weight of the filler, and preferably in a content of 0.1% to 2.5% by weight of the filler. The chemical structure of the silane coupling agent is represented by the general formula 3:

[0047]

[0048] wherein m is an integer of 1 to 3, and n is an integer of 0 to 3; R 1 selected from

[0049] wherein j is selected from a hydrogen atom, or an alkyl group having a carbon number of 1 to 6; R 2 and R 3 are each independently selected from a methyl group or an ethyl group, and in the case where a plurality of R 2 and R 3 may be the same or different from each other.

[0050] The silane coupling agent can be selected from one or more of γ-(2,3-epoxypropoxy)propyltrimethoxysilane, trimethyloxyphenylsilane, 3-aminopropyltriethoxysilane, 3-(isobutyryloxy)propyltrimethoxysilane, vinyltrimethoxysilane, (3-aminopropyl)triethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, γ-anilinopropyltrimethoxysilane, γ-anilinopropyltriethoxysilane, γ-anilinopropylmethyldimethoxysilane, γ-anilinopropylmethyldiethoxysilane, γ-anilinopropylethyldiethoxysilane, γ-anilinopropylethyldimethoxysilane, γ-anilinomethyltrimethoxysilane, γ-anilinomethyltriethoxysilane, γ-anilinomethyldimethoxysilane, γ-anilinomethyldiethoxysilane, γ-anilinomethylethyldiethoxysilane, γ-anilinomethylethyldimethoxysilane, and the like.

[0051] From the aspect of fluidity, the silane coupling agent can be selected from one or more of the amino organosilane coupling agents of general chemical structure 3-1, which, when mixed into the epoxy resin system, can improve the adhesion of the filler to the resin and better play the bulk properties of the filler. The amino organosilane coupling agents of general chemical structure 3-1 include γ-anilinopropyltrimethoxysilane, γ-anilinopropyltriethoxysilane, γ-anilinopropylmethyldimethoxysilane, γ-anilinopropylmethyldiethoxysilane, γ-anilinopropylethyldiethoxysilane, γ-anilinopropylethyldimethoxysilane, and the like. More preferably, the silane coupling agent is γ-anilinopropyltrimethoxysilane.

[0052]

[0053] wherein m is an integer of 1-3; n is an integer of 0-3; (X) j selected from a hydrogen atom, an alkyl group having a carbon atom number of 1-6; R 2 , R 3 are each independently selected from a methyl group or an ethyl group, and in R 2 or R 3 When there are multiple, they can be the same or different.

[0054] The stress release agent is preferably an organosilicon compound, preferably the mass of the organosilicon compound is 0.5%-2% of the mass of the epoxy encapsulant. The release agent is a linear saturated carboxylic acid and / or an oxidized polyethylene wax, wherein the number average molecular weight of the oxidized polyethylene wax is 550-1200, more preferably the number average molecular weight of the oxidized polyethylene wax is 800-1000. The colorant is preferably a carbon black colorant.

[0055] The flame retardant is an ester of phosphoric acid with an alcohol or with a phenol, such as trimethyl phosphate, triethyl phosphate, triphenyl phosphate, dihydroxyphenyl phosphate, tridihydroxyphenyl phosphate, and the like. From the viewpoint of hydrolysis resistance, an aromatic condensed phosphate having the chemical structural formula 4 is preferably used:

[0056]

[0057] The amount of the flame retardant is preferably 0.2% to 0.5% by mass of phosphorus atoms, relative to the total amount of the other components except for the filler. If it is less than 0.2%, problems such as lead misalignment and molding cavity are likely to occur. If it is more than 3%, the moldability and moisture resistance are reduced.

[0058] The fumed silica is preferably fumed silica, and is not particularly limited as long as it is a substance generally used in an encapsulation epoxy resin composition. Preferably, the average particle diameter of the fumed silica is in the range of 5 to 40 nm, and the amount of the fumed silica is preferably 0.2% to 0.5% by mass, relative to the amount of the epoxy encapsulation material.

[0059] In addition, the high-thermal-conductivity epoxy encapsulation material of the present application can further include an ion-trapping agent and / or other auxiliary agents.

[0060] The present application also provides a method for producing the high-thermal-conductivity epoxy encapsulation material as described above, comprising the following steps:

[0061] The components are weighed in proportion, and then kneaded and mixed at an extrusion temperature of 100 to 140°C, cooled, and finely pulverized to obtain the epoxy encapsulation material.

[0062] The present application also provides a use of the high-thermal-conductivity epoxy encapsulation material as described above in semiconductor encapsulation.

[0063] Examples

[0064] The synthesis process of the liquid crystal type epoxy resin having the chemical structural formula 2-1 (denoted as A2-1) is as follows:

[0065] (1) The synthesis process of the liquid crystal type epoxy resin having the chemical structural formula 2-1 (denoted as A2-1) is as follows:

[0066] A 200 mL 95% ethanol solution was placed in a three-necked flask under a nitrogen atmosphere, and sodium hydrosulfite was added, followed by the addition of hydroquinone and dibromobutane, and stirred for 1 h. A potassium hydroxide solution was added dropwise into the system, and heated to reflux for 8 h, and then cooled to room temperature. 95% ethanol was continuously added, and the insoluble monobutyl phenol and dibutyl phenyl ether were filtered off, and the filter cake was washed with hot ethanol twice, and the mother liquor was combined. The ethanol was evaporated by rotary evaporation, and the remaining solid was washed with 1 L distilled water three times, and dried at high temperature to remove water and unreacted dibromobutane. The crude product was recrystallized from 95% ethanol to obtain compound

[0067] At 25°C, 4-hydroxybenzoic acid and methanol were added, and after the acid was completely dissolved, a solution of potassium hydroxide and water was slowly added dropwise, then allyl bromide was added, and heated to reflux for 8 hours. As the reaction proceeded, potassium bromide precipitated, which was filtered and the methanol was rotary evaporated. The system was cooled to room temperature, and 2.5 L of distilled water was added, and the organic matter was washed with 250 ml of petroleum ether, and the aqueous phase was separated. 20% hydrochloric acid was added to the aqueous phase until the pH of the system was slightly excessive, and the precipitate was the target crude product. After recrystallization with ethanol, the compound

[0068] Compound was added under anhydrous conditions, and chlorosulfoxide was added dropwise with a few drops of pyridine, and heated to reflux for 8 h, and the excess chlorosulfoxide was removed under vacuum, and cooled to room temperature to obtain a yellow liquid.

[0069] Compound was dissolved in 50 ml of pyridine, and the yellow liquid was added dropwise, and after reaction at room temperature for 4 h, it was poured into 1 L of water, and the precipitate was collected by filtration, and the precipitate was washed with 1 L of water and dried. Recrystallization with methanol obtained the target product.

[0070] (2) Synthesis process of liquid crystal type epoxy resin of chemical structure 2-2 (denoted as A2-2):

[0071] Dihydroxydiphenyl, 6-bromo-1-hexene, and potassium carbonate were added to 100 ml of acetone and heated to reflux for 24 hours. The inorganic salt was filtered off, and the acetone was rotary evaporated, and the remaining solid was washed with excess water and ethanol, and dried to obtain compound a

[0072] Compound a and 3-chloroperbenzoic acid were dissolved in 50 ml of dichloromethane and heated to reflux for 3 days. After the reaction was completed, the insoluble matter was filtered off, and the dichloromethane solution was washed with excess 5% sodium sulfite solution, 5% sodium carbonate solution, and saturated sodium chloride solution, respectively. After drying with anhydrous magnesium sulfate, the dichloromethane was rotary evaporated, and the crude product was recrystallized with isopropanol to obtain the target product.

[0073] (3) Synthesis process of liquid crystal type epoxy resin of chemical structure 2-3 (denoted as A2-3):

[0074] p-Hydroxybenzaldehyde and 450 ml of methanol were poured into a three-necked flask, and p-phenylenediamine was dissolved in 300 ml of methanol solution and added dropwise into the system, and stirred at room temperature for 18 h. After the reaction was completed, the precipitate was filtered, washed with 3 L of methanol, and dried to obtain compound

[0075] Compound b, epichlorohydrin, 50 ml DMF, a small amount of benzyl triethyl ammonium bromide were poured into a three-necked flask and stirred for 1 h. 20 ml of 40% concentration sodium hydroxide solution was added dropwise, refluxed at 100°C for 10 h, after the reaction was completed, it was cooled to room temperature, poured into 300 ml of methanol to precipitate the product, the solid was filtered, washed with excess water and methanol to obtain the crude product. Isopropanol recrystallization to obtain the target product.

[0076] (4) Synthesis process of liquid crystal type epoxy resin of chemical structural formula 2-4 (denoted as A2-4):

[0077] P-phenylenediamine, 20 ml of tetrahydrofuran and 1.5 ml of pyridine were poured into a three-necked flask, p-phthaloyl chloride was dissolved in 5 ml of tetrahydrofuran and slowly added dropwise into the system at room temperature, and stirred for 12 h. After the reaction was completed, it was filtered, the precipitate was washed with tetrahydrofuran and a large amount of water, and dried to obtain compound

[0078] Compound c, epichlorohydrin, benzyl triethyl ammonium bromide were poured into a three-necked flask and reacted at 80°C for 3 h. The epichlorohydrin was rotary evaporated, excess toluene solvent was added, 20% sodium hydroxide solution was added dropwise, and reacted at 80°C for 4 h. After the reaction was completed, it was cooled to room temperature, washed with water, separated into organic and aqueous phases, and the organic phase was rotary evaporated to obtain the crude product. Isopropanol recrystallization to obtain the target product.

[0079] (5) Synthesis process of liquid crystal type epoxy resin of chemical structural formula 2-5 (denoted as A2-5):

[0080] P-phenylenediamine, 20 ml of tetrahydrofuran and 1.5 ml of pyridine were poured into a three-necked flask, p-phthaloyl chloride was dissolved in 5 ml of tetrahydrofuran and slowly added dropwise into the system at room temperature, and stirred for 12 h. After the reaction was completed, it was filtered, the precipitate was washed with tetrahydrofuran and a large amount of water, and dried to obtain compound

[0081] (6) Synthesis process of liquid crystal type epoxy resin of chemical structural formula 2-5 (denoted as A2-6):

[0082] P-phenylenediamine, 20 ml of tetrahydrofuran and 1.5 ml of pyridine were poured into a three-necked flask, p-phthaloyl chloride was dissolved in 5 ml of tetrahydrofuran and slowly added dropwise into the system at room temperature, and stirred for 12 h. After the reaction was completed, it was filtered, the precipitate was washed with tetrahydrofuran and a large amount of water, and dried to obtain compound

[0083] The materials used in the following examples and comparative examples are described as follows:

[0084] The encapsulating epoxy resin A1-1 is YX-4000H available from Japan Epoxy Resin Inc. and its general chemical structure is shown in Formula 1-1.

[0085] The encapsulating epoxy resin A1-2 is a phenyl aralkyl type epoxy resin (epoxy equivalent weight: 285, softening point: 63°C, available from Nippon Kayaku, trade name NC-3000) and its general chemical structure is shown in Formula 1-2.

[0086] The phenol resin B1 is a biphenyl aralkyl type phenol resin (hydroxyl equivalent weight: 203, softening point: 65°C, available from Meiwa Plastic Industries, Ltd., trade name MEH-7851SS).

[0087] The phenol resin B2 is a phenol novolak resin (hydroxyl equivalent weight: 104, softening point: 60°C, available from Sumitomo Bakelite Co., Ltd., trade name PR-HF-3).

[0088] The filler is AI2O3 powder with an average particle size of 5-8 μm and a cut-off particle size of 53 μm, available from Denka.

[0089] The curing accelerator is triphenylphosphine. The silane coupling agent is γ-aminopropyltrimethoxysilane. The flame retardant is trimethyl phosphate.

[0090] The stress releasing agent is an organosilicon compound, KF-6123, available from Shin-Etsu Chemical Co., Ltd.

[0091] The release agent is an oxidized polyethylene wax with a number average molecular weight of 1000, HW-4252E, available from Mitsui Chemicals, Inc.

[0092] The colorant is carbon black, MA-600, available from Mitsubishi Chemical Corporation.

[0093] The fumed silica is nano-sized silicon dioxide with an average particle size of 5-40 nm and a specific surface area of 300 ± 30 m 2 / g.

[0094] Example 1-10

[0095] The preparation process of the high thermal conductive epoxy molding compound is as follows:

[0096] The epoxy resin, phenol resin, filler, curing accelerator, silane coupling agent, stress releasing agent, release agent, colorant, flame retardant and fumed silica are mixed and kneaded at an extrusion temperature of 120°C, cooled, finely pulverized and finally obtained as the high thermal conductive epoxy molding compound.

[0097] The preparation processes of the high-thermal-conductivity epoxy encapsulating materials of Examples 1-10 are different in that the specific material selection and / or content of each component are different, which are embodied in Table 1 below. The unit of the content of each component in the table is parts by weight.

[0098] Table 1 Formulation table of the high-thermal-conductivity epoxy encapsulating materials in Examples 1-10

[0099]

[0100]

[0101] Comparative Examples 1-5

[0102] The preparation processes of the epoxy encapsulating materials are as follows:

[0103] The epoxy resin, phenolic resin, filler, curing accelerator, silane coupling agent, stress release agent, release agent, colorant, flame retardant and fumed silica are mixed, and then kneaded and mixed at an extrusion temperature of 120℃, cooled, finely pulverized, and finally obtained as the epoxy encapsulating material.

[0104] The preparation processes of the epoxy encapsulating materials of Comparative Examples 1-5 are different in that the specific material selection and / or content of each component are different, which are embodied in Table 2 below. The unit of the content of each component in the table is parts by weight.

[0105] Table 2 Formulation table of the epoxy encapsulating materials in Comparative Examples 1-5

[0106]

[0107]

[0108] The performance tests of the epoxy encapsulating materials prepared in Examples 1-10 and Comparative Examples 1-5 are as follows:

[0109] (1) Glass transition temperature, test standard GB / T 40564-2021.

[0110] (2) Bending strength, test standard GB / T 40564-2021.

[0111] (3) Thermal conductivity, test standard GB / T 40564-2021.

[0112] (4) Continuous molding property, judgment standard: continuous molding for 300 times without mold stains is excellent; continuous molding for 300 times with mold stains is good; continuous molding for less than 300 times is general. A represents “excellent”, B represents “good”, and C represents “general”.

[0113] (5) Economy, the judgment standard is: the comprehensive cost is less than the ordinary EMC cost, which is excellent; the ordinary EMC cost is less than the comprehensive cost, which is less than 1.1 times of the ordinary EMC cost, which is good; the comprehensive cost is more than 1.1 times of the ordinary EMC cost, which is general. A represents "excellent", B represents "good", and C represents "general".

[0114] The performance test results of the epoxy plastic encapsulating material prepared in Examples 1-10 and Comparative Examples 1-5 are shown in Table 3 below:

[0115] Table 2 Performance test results of the epoxy plastic encapsulating material prepared in Examples 1-10 and Comparative Examples 1-5

[0116]

[0117]

[0118] It should be noted that "\ " in Table 3 represents that the sample is not successfully prepared, and there is no test data.

[0119] From the test results, it can be found that the introduction of the liquid crystal type epoxy resin can effectively improve the thermal conductivity of the plastic encapsulating material by comparing Comparative Examples 1-6 and Comparative Examples 1-5. However, considering the process and economy, it is considered that the liquid crystal type epoxy resin A2-2 can balance the performance, process and economy. The influence of the filler content on the thermal conductivity can be summarized by comparing Comparative Example 2 and Examples 7-10. When the filler content is from 87.5% to 91%, good process and economy can be maintained, and the thermal conductivity can be up to 5.32 W / m·K. By comparing Comparative Examples 7-10 and Comparative Examples 2-5, it can be found that when the filler content is 87.5%, the formula can balance the process and economy, but the thermal conductivity is much lower than that of the liquid crystal type epoxy resin system formula with the same filler content. When the filler content exceeds 87.5%, the overall process of the formula is poor, and it is difficult to prepare the sample.

[0120] The high-thermal-conductivity epoxy plastic encapsulating material of the present application has the following beneficial effects compared with the prior art:

[0121] The conventional resin system epoxy plastic encapsulating material cannot meet the high thermal conductivity while balancing the reliability and good process formability. However, the high-thermal-conductivity epoxy plastic encapsulating material of the present application selects the liquid crystal type epoxy resin and spherical aluminum oxide filler to improve the thermal conductivity of the epoxy plastic encapsulating material and maintain good continuous formability, and selects the stress release agent to reduce the modulus, which balances the reliability, so that the epoxy plastic encapsulating material has good reliability and continuous formability while having high thermal conductivity.

[0122] The above only describes the preferred embodiments of the present application, and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A high thermal conductivity epoxy molding compound, characterized in that: The invention comprises the following components: epoxy resin, phenolic resin, filler, curing accelerator, silane coupling agent, stress release agent, colorant, flame retardant, release agent and fumed silicon; Wherein, the mass of the epoxy resin is 4% to 25% of the mass of the molding compound, the mass of the phenolic resin is 3% to 15% of the mass of the molding compound, the mass of the filler is 60% to 93% of the mass of the molding compound, the mass of the curing accelerator is 0.05% to 2% of the mass of the molding compound, the mass of the silane coupling agent is 0.05% to 5% of the mass of the filler, the mass of the stress release agent is 0.5% to 5% of the mass of the filler, the mass of the release agent is 0.005% to 2% of the mass of the molding compound, the mass of the colorant is 0.1% to 0.6% of the mass of the molding compound, the mass of the flame retardant is 0.1% to 0.5% of the mass of the molding compound, and the mass of the fumed silicon is 0.1% to 0.5% of the mass of the molding compound; The epoxy resin is an encapsulation epoxy resin and a liquid crystal epoxy resin; The encapsulation epoxy resin is an epoxy resin of the following chemical structural formula 1-2; Wherein, n is independently an integer of any value from 1 to 3; The liquid crystal epoxy resin is at least one of the epoxy resins of the following chemical formulas 2-1, 2-2, and 2-5; The phenolic resin is a biphenyl aralkyl type phenolic resin or a phenol novolac resin; The filler is an inorganic filler, and the inorganic filler is spherical alumina; the average particle size of the inorganic filler is 5 to 8 μm; The curing accelerator is triphenylphosphine; The silane coupling agent is γ-anilinopropyltrimethoxysilane; The stress release agent is an organosilicon compound; The release agent is oxidized polyethylene wax, wherein the number average molecular weight of the oxidized polyethylene wax is 550-1200; the colorant is a carbon black agent; The flame retardant is trimethyl phosphate; The gas-phase silicon is gas-phase silicon dioxide, and the average particle size is 5 to 40 nm.

2. The high thermal conductivity epoxy molding compound according to claim 1, characterized in that: The epoxy resin includes 3 parts by weight of encapsulation epoxy resin and 2.56 parts by weight of liquid crystal epoxy resin; Or, the epoxy resin includes 3 parts by weight of encapsulation epoxy resin and 2.09 parts by weight of liquid crystal epoxy resin; Or, the epoxy resin includes 3 parts by weight of encapsulation epoxy resin and 1.78 parts by weight of liquid crystal epoxy resin; Or, the epoxy resin includes 2.67 parts by weight of an encapsulation epoxy resin and 1.86 parts by weight of a liquid crystal epoxy resin; Or, the epoxy resin includes 2.33 parts by weight of an encapsulation epoxy resin and 1.63 parts by weight of a liquid crystal epoxy resin; Or, the epoxy resin includes 2.00 parts by weight of an encapsulation epoxy resin and 1.39 parts by weight of a liquid crystal epoxy resin; Alternatively, the epoxy resin includes 3.33 parts by weight of an encapsulation epoxy resin and 2.32 parts by weight of a liquid crystal epoxy resin.

3. The high thermal conductivity epoxy molding compound according to claim 1, characterized in that: The ratio of the total number of epoxy groups in the epoxy resin to the total number of hydroxyl groups in the phenolic resin, that is, the equivalent ratio, is 0.5-2.

4. The high thermal conductivity epoxy molding compound according to claim 1, characterized in that: The phenolic resin includes 2.28 parts by weight of a biphenyl aralkyl type phenolic resin and 1.17 parts by weight of a phenol novolac resin; Or, the phenolic resin includes 2.59 parts by weight of a biphenyl aralkyl type phenolic resin and 1.33 parts by weight of a phenol novolac resin; Or, the phenolic resin includes 2.79 parts by weight of a biphenyl aralkyl type phenolic resin and 1.43 parts by weight of a phenol novolac resin; Or, the phenolic resin includes 2.30 parts by weight of a biphenyl aralkyl type phenolic resin and 1.18 parts by weight of a phenol novolac resin; Or, the phenolic resin includes 2.01 parts by weight of a biphenyl aralkyl type phenolic resin and 1.03 parts by weight of a phenol novolac resin; Or, the phenolic resin includes 1.73 parts by weight of a biphenyl aralkyl type phenolic resin and 0.88 parts by weight of a phenol novolac resin; Alternatively, the phenolic resin includes 2.87 parts by weight of a biphenyl aralkyl type phenolic resin and 1.47 parts by weight of a phenol novolac resin.

5. The high thermal conductivity epoxy molding compound according to claim 1, characterized in that: Also included are ion traps.

6. A method for preparing the high thermal conductivity epoxy molding compound according to any one of claims 1 to 5, characterized in that: The following steps are involved: The components are weighed in proportion, and then kneaded and mixed at an extrusion temperature of 100-140° C., cooled, and finely pulverized to obtain the epoxy molding compound.

7. Use of the high thermal conductivity epoxy molding compound according to any one of claims 1 to 5 in semiconductor packaging.

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