Epoxy resin material as well as preparation method and application thereof

Abstract

The invention relates to the technical field of electronic packaging, and discloses an epoxy resin material and a preparation method and application thereof.The epoxy resin material comprises first epoxy resin, a curing agent, an ion capturing agent, a low-stress modifier, a first coupling agent, an accelerant, a coloring agent, a flame retardant, a release agent, a hydroxide / epoxy resin mixture and solid filler; the hydroxide / epoxy resin mixture is obtained by mixing hydroxide, second epoxy resin, a second coupling agent and a dispersing agent and then extruding; the second coupling agent is a silane coupling agent; the accelerant is a mixture of an imidazole compound and an organic phosphorus compound. The continuous molding stability of the epoxy resin material reaches more than 400 molds, the surfaces of the molds and a packaging body are not dirty, the problems of mold sticking and tension crack do not occur, good process operability is displayed, the production efficiency is improved, and the cost pressure caused by mold cleaning and moistening is reduced; meanwhile, the epoxy resin material can pass MSL1 layering and reliability testing, and the product quality is high.

Description

Technical Field

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

[0002] Epoxy resin materials for semiconductor packaging, namely epoxy molding compounds (EMC), are compounded from epoxy resin, curing agent, filler, accelerator, stress modifier, coupling agent, release agent, colorant and other trace additives. With the market trend of miniaturization, lightweight and high performance of electronic equipment, the high integration and multi-pin of electronic components are developing year by year, so the requirements for epoxy resin materials for packaging semiconductor components are increasing day by day.

[0003] For small-sized packages with high reliability requirements, more attention should be paid to the balance between demolding and reliability. EMC for small-sized packages generally needs to be designed as a low-filler system with a weight percentage of 70-77% to ensure a large mold shrinkage rate to prevent mold sticking and cracking; however, the low-filler EMC system has a high moisture absorption rate, which often leads to electrical failure. Hydroxides can act as flame retardants, adjust the pH value of the system, improve the pass rate of electrical tests, and have the advantage of low cost. Therefore, low-filler EMC systems generally choose to add a large amount of hydroxide. However, the large addition of hydroxide will make the EMC operability worse, resulting in mold sticking and cracking, and it is difficult to apply to small-sized packages. Therefore, how to solve the operability problems caused by the addition of hydroxide to EMC is a difficult problem that needs to be solved urgently in this field.

[0004] Moreover, when the epoxy resin material has high moisture resistance, the lower modulus and higher adhesion often reduce the number of continuous encapsulation modules; because as the number of modules increases, semiconductor products are very prone to mold cracking, requiring customers to frequently clean the mold. At present, there are no reports of epoxy resin materials with hydroxide added that can pass the copper frame MSL1 moisture sensitivity level assessment and have a continuous encapsulation module of more than 400 modules. Summary of the invention

[0005] The purpose of the present invention is to overcome the problems existing in the prior art and to provide an epoxy resin material and a preparation method and application thereof. After the epoxy resin material is encapsulated in a semiconductor, it can pass the MSL1 moisture sensitivity level assessment and the continuous encapsulation module can reach more than 400 modules.

[0006] The inventors of the present invention have discovered through research that, by designing the raw material components and by mixing and pre-extruding the hydroxide, epoxy resin, silane coupling agent and dispersant, the hydroxide can be modified by the silane coupling agent to obtain a hydroxide / epoxy resin mixture modified by a coupling agent under a specific process. When the epoxy resin material containing the hydroxide / epoxy resin mixture is used in EMC, it can exhibit good operability and high reliability.

[0007] In order to achieve the above object, the present invention provides an epoxy resin material on one hand, wherein the epoxy resin material comprises a first epoxy resin, a curing agent, an ion capture agent, a low stress modifier, a first coupling agent, an accelerator, a colorant, a flame retardant, a release agent, a hydroxide / epoxy resin mixture and a solid filler;

[0008] Wherein, the hydroxide / epoxy resin mixture is obtained by mixing hydroxide, a second epoxy resin, a second coupling agent and a dispersant, and then extruding; the second coupling agent is a silane coupling agent;

[0009] The accelerator is a mixture of an imidazole compound and an organic phosphorus compound.

[0010] Preferably, the hydroxide / epoxy resin mixture is prepared according to the following process:

[0011] A1. Stir and mix the hydroxide and the second epoxy resin, add the second coupling agent and the dispersant during the stirring process, and continue stirring to obtain a mixed powder;

[0012] A2. Extruding the mixed powder.

[0013] Preferably, the weight ratio of the hydroxide, the second epoxy resin, the silane coupling agent and the dispersant is 80:4-35:0.9-11:0.08-1.1;

[0014] Preferably, the second coupling agent is selected from one or more of 3-glycidyloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and N-phenyl-3-aminopropyltrimethoxysilane;

[0015] Preferably, the second epoxy resin is selected from one or more of o-cresol novolac epoxy resin, dicyclopentadiene epoxy resin, phenol biphenyl alkyl epoxy resin, trisphenol methane multifunctional epoxy resin, biphenyl epoxy resin, naphthol aralkyl epoxy resin, tetramethyl bisphenol F epoxy resin and naphthalene ring epoxy resin, preferably a mixture of o-cresol novolac epoxy resin and biphenyl epoxy resin.

[0016] Preferably, the dispersant is selected from one or more of trimethyl stearamide chloride, alkyl aryl phosphates and alkyl benzene sulfonates.

[0017] Preferably, the hydroxide is selected from aluminum hydroxide and / or magnesium hydroxide.

[0018] Preferably, the extrusion is carried out in a twin-screw extruder;

[0019] Preferably, the extrusion conditions include: a temperature of 80-140° C. and a screw speed of 50-250 rpm.

[0020] Preferably, before step A1, the method further comprises: crushing the second epoxy resin; in step A1, the stirring and mixing time is 3-10 minutes;

[0021] Preferably, in step A1, the stirring time is continued for 3-10 min.

[0022] Preferably, based on the total weight of the epoxy resin material as 100 weight %, the content of the first epoxy resin is 8-15 weight %, the content of the curing agent is 3-8 weight %, the content of the ion capture agent is 0.1-1 weight %, the content of the low stress modifier is 0.01-1 weight %, the content of the first coupling agent is 0.2-1.5 weight %, the content of the accelerator is 0.1-1 weight %, the content of the colorant is 0.1-1 weight %, the content of the flame retardant is 0.1-5 weight %, the content of the release agent is 0.1-1 weight %, the content of the hydroxide / epoxy resin mixture is 1-25 weight %, and the content of the solid filler is 50-85 weight %.

[0023] Preferably, the flame retardant is a non-hydroxide flame retardant;

[0024] Preferably, the solid filler is a non-hydroxide solid filler;

[0025] Preferably, the first coupling agent is a silane coupling agent;

[0026] Preferably, the first epoxy resin is selected from one or more of o-cresol type epoxy resin, dicyclopentadiene type epoxy resin, phenol biphenyl alkyl type epoxy resin, trisphenol methane type multifunctional epoxy resin, biphenyl type epoxy resin, naphthol aralkyl type epoxy resin, tetramethyl bisphenol F type epoxy resin and naphthalene ring type epoxy resin, preferably a mixture of o-cresol type epoxy resin and biphenyl type epoxy resin;

[0027] Preferably, the curing agent is a phenolic resin curing agent;

[0028] Preferably, the flame retardant is selected from one or more of halogen flame retardants, phosphorus flame retardants, nitrogen flame retardants, phosphorus-halogen flame retardants and phosphorus-nitrogen flame retardants;

[0029] Preferably, the solid filler is selected from one or more of crystalline silica, fused silica, alumina and metal nitride, preferably a mixture of crystalline silica and fused silica;

[0030] Preferably, the first coupling agent is selected from one or more of 3-glycidyloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and N-phenyl-3-aminopropyltrimethoxysilane;

[0031] Preferably, the curing agent is selected from one or more of linear phenolic resin, phenolic aralkyl resin containing a phenylene skeleton, phenolic aralkyl resin containing a biphenylene skeleton, trihydroxyphenylmethane type multifunctional phenolic resin and naphthol aralkyl type phenolic resin;

[0032] Preferably, the accelerator is a mixture of triphenylphosphine and 2-phenyl-4-methylimidazole.

[0033] The second aspect of the present invention provides a method for preparing the epoxy resin material as described above, the method comprising: mixing a hydroxide / epoxy resin mixture, a solid filler, a colorant and an ion capture agent, a first epoxy resin, a curing agent, an accelerator, a release agent, a solid stress modifier and a low stress modifier, and then extruding, and cooling, crushing and molding the obtained extruded product;

[0034] Preferably, a twin-screw extruder is used for extrusion;

[0035] Preferably, the extrusion conditions include: a temperature of 80-140° C. and a screw speed of 50-250 rpm.

[0036] A third aspect of the present invention provides use of the epoxy resin material as described above or the epoxy resin material prepared by the method as described above in semiconductor packaging.

[0037] The epoxy resin material for semiconductor packaging provided by the present invention can pass MSL1 stratification and reliability tests after the epoxy resin material encapsulates the semiconductor through the design of raw material components, and the product quality is high; on this basis, the hydroxide is modified through pre-extrusion, so that the continuous molding stability of the obtained epoxy resin material reaches more than 400 molds, which is greatly improved compared with the existing 200 mold packaging level. The surface of the mold and the packaging body is not dirty, and there is no problem of mold sticking and cracking, which shows good process operability, improves production efficiency, and reduces the cost pressure caused by cleaning the mold. DETAILED DESCRIPTION

[0038] The specific embodiments of the present invention are described in detail below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0039] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0040] The present invention provides an epoxy resin material, which comprises a first epoxy resin, a curing agent, an ion capture agent, a low stress modifier, a first coupling agent, an accelerator, a colorant, a flame retardant, a release agent, a hydroxide / epoxy resin mixture and a solid filler;

[0041] Wherein, the hydroxide / epoxy resin mixture is obtained by mixing hydroxide, a second epoxy resin, a second coupling agent and a dispersant, and then extruding; the second coupling agent is a silane coupling agent;

[0042] The accelerator is a mixture of an imidazole compound and an organic phosphorus compound.

[0043] In the present invention, the first epoxy resin and the second epoxy resin may be the same or different; the first coupling agent and the second coupling agent may be the same or different.

[0044] It is difficult to add hydroxide to organic materials. The large amount of hydroxide added will make the EMC operability worse, resulting in sticking and cracking, and it is difficult to be applied to small-sized packaging. Taking aluminum hydroxide as an example, the raw aluminum hydroxide particles are spherical particles with a large diameter. They are large particles formed by the polymerization of multiple small crystals. Due to the crystal orientation during growth, some particles have uneven surfaces on the crystal surface. The surface of aluminum hydroxide has hydrophilic properties, while the surface of organic synthetic materials is quite different from it. It is very difficult to add powder to organic materials. Due to the irregularity of aluminum hydroxide particles themselves and the structural differences with organic polymers, aluminum hydroxide has the disadvantages of low bonding force with polymers, poor compatibility and poor dispersion in polymers. In the EMC system, the uneven surface state of aluminum hydroxide can directly affect the leveling and surface uniformity of EMC materials, and thus affect operability. At the same time, the uneven dispersion of aluminum hydroxide particles will also affect the strength and mechanical properties of organic polymer products. Stress concentration will occur in places where the particles are larger, making the material fragile, resulting in uneven surface strength of EMC materials when demolding, thus causing sticking problems. In the present invention, a silane coupling agent is used to modify the hydroxide. The silane coupling agent contains two ends with different properties. The alkoxy group is reactive to inorganic substances, while the long-chain alkyl group is reactive or compatible to organic substances. When the silane coupling agent is between the inorganic and organic interfaces, a bonding layer of an organic matrix-silane coupling agent-inorganic matrix can be formed, thereby combining two materials with poor bonding strength. Dry modification is simple to operate but has limited modification effects. The present invention uses the strong mixing effect of a twin-screw extruder to modify aluminum hydroxide on the basis of dry modification, so that the modified hydroxide / epoxy resin mixture can achieve better operability.

[0045] In order to make the prepared hydroxide / epoxy resin mixture more operable, in a preferred embodiment, the hydroxide / epoxy resin mixture is prepared according to the following process:

[0046] A1. Stir and mix the hydroxide and the second epoxy resin, add the second coupling agent and the dispersant during the stirring process, and continue stirring to obtain a mixed powder;

[0047] A2. Extruding the mixed powder.

[0048] In some embodiments, in step A1, the weight ratio of the hydroxide, the second epoxy resin, the silane coupling agent and the dispersant is 80:4-35:0.9-11:0.08-1.1.

[0049] In the present invention, the second coupling agent used to prepare the hydroxide / epoxy resin mixture is a silane coupling agent, which can be a commonly used silane coupling agent in the art. In a preferred embodiment, the second coupling agent is selected from one or a mixture of 3-glycidyloxypropyltrimethoxysilane (KH560), 3-mercaptopropyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, etc.

[0050] In the present invention, the dispersant used to prepare the hydroxide / epoxy resin mixture can be a conventional dispersant in the art. In some embodiments, the dispersant is selected from one or more of trimethyl stearamide chloride, alkyl aryl phosphate and alkyl benzene sulfonate.

[0051] In some embodiments, the hydroxide is selected from aluminum hydroxide and / or magnesium hydroxide.

[0052] The present invention does not limit the specific selection of the second epoxy resin, and it can be an epoxy resin commonly used in the field of semiconductor packaging to meet specific packaging performance requirements. In a preferred embodiment, the second epoxy resin is selected from one or more of o-cresol type epoxy resin (EOCN), dicyclopentadiene type epoxy resin (DCPD), phenol biphenyl alkyl type epoxy resin (MAR), trisphenol methane type multifunctional epoxy resin, biphenyl type epoxy resin (BP), naphthol aralkyl type epoxy resin, tetramethyl bisphenol F type epoxy resin and naphthalene ring type epoxy resin, preferably a mixture of o-cresol type epoxy resin and biphenyl type epoxy resin. Further preferably, in the second epoxy resin, the weight ratio of the amount of the o-cresol type epoxy resin and the biphenyl type epoxy resin is 1:0.5~2.

[0053] In a preferred embodiment, when preparing the hydroxide / epoxy resin mixture, before step A1, the process further includes: pulverizing the second epoxy resin.

[0054] In some embodiments, in step A1, the stirring and mixing time is 3-10 min.

[0055] In some embodiments, in step A1, the stirring time is continued for 3-10 minutes.

[0056] In a preferred embodiment, in step A2, the extrusion is carried out in a twin-screw extruder.

[0057] In a preferred embodiment, in step A2, the extrusion conditions include: a temperature of 80-140°C and a screw speed of 50-250rpm. Specifically, the extrusion temperature may be 80°C, 85°C, 90°C, 100°C, 110°C, 120°C, 130°C or 140°C; the screw speed during extrusion may be 50rpm, 60rpm, 70rpm, 90rpm, 100rpm, 150rpm, 200rpm, 220rpm or 250rpm.

[0058] In a more preferred embodiment, in step A2, the extrusion conditions include: a temperature of 100-130° C. and a screw speed of 150-200 rpm.

[0059] In a specific embodiment, the hydroxide / epoxy resin mixture is prepared according to the following process: the hydroxide and the crushed second epoxy resin are placed in a high mixing tank and mixed and stirred for 3-10 minutes, and the second coupling agent and dispersant are sprayed into the mixing and stirring process, and stirring is continued for 3-10 minutes after spraying; the mixed powder is extruded through a twin-screw extruder at a temperature of 80-140° C. and a screw speed of 50-250 rpm, and the extruded product is crushed after cooling for use.

[0060] In the epoxy resin material of the present invention, preferably, based on the total weight of the epoxy resin material as 100 weight %, the content of the first epoxy resin is 8-15 weight %, the content of the curing agent is 3-8 weight %, the content of the ion capture agent is 0.1-1 weight %, the content of the low stress modifier is 0.01-1 weight %, the content of the first coupling agent is 0.2-1.5 weight %, the content of the accelerator is 0.1-1 weight %, the content of the colorant is 0.1-1 weight %, the content of the flame retardant is 0.1-5 weight %, the content of the release agent is 0.1-1 weight %, the content of the hydroxide / epoxy resin mixture is 1-25 weight %, and the content of the solid filler is 50-85 weight %. Within the above dosage range, the obtained epoxy resin material has better reliability and operability.

[0061] Further preferably, based on the total weight of the epoxy resin material as 100 weight %, the content of the first epoxy resin is 8-13 weight %, the content of the curing agent is 4-7 weight %, the content of the ion capture agent is 0.1-0.4 weight %, the content of the low stress modifier is 0.05-0.8 weight %, the content of the first coupling agent is 0.3-1.1 weight %, the content of the accelerator is 0.1-0.5 weight %, the content of the colorant is 0.1-0.6 weight %, the content of the flame retardant is 0.1-3 weight %, the content of the release agent is 0.1-0.8 weight %, the content of the hydroxide / epoxy resin mixture is 5-20 weight %, and the content of the solid filler is 55-75 weight %.

[0062] In the present invention, the flame retardant is a flame retardant other than hydroxide. In some embodiments, the flame retardant is a halogen flame retardant and / or a non-halogen flame retardant other than hydroxide. In a preferred embodiment, the flame retardant is selected from one or more of halogen flame retardants, phosphorus flame retardants, nitrogen flame retardants, phosphorus-halogen flame retardants and phosphorus-nitrogen flame retardants, and the type and amount can be matched according to actual conditions. Among them, the phosphorus flame retardant can be triphenylphosphine oxide, hexaphenoxy cyclotriphosphazene, and the phosphorus-nitrogen flame retardant can be polyphosphazene FP-100.

[0063] In the present invention, the solid filler is a solid filler other than hydroxide. The present invention does not limit the specific type of the solid filler other than hydroxide, and it can be one or more of commonly used inorganic fillers such as silicon dioxide, aluminum oxide, and metal nitride.

[0064] In a preferred embodiment, the solid filler is selected from one or more of crystalline silica, fused silica, alumina and metal nitride, and more preferably a mixture of crystalline silica and fused silica. Further preferably, in the solid filler, the weight ratio of crystalline silica to fused silica is 1:4-8.

[0065] In some embodiments, the solid filler may be spherical or angular, and the maximum particle size may be 10 μm, 20 μm, 30 μm, 45 μm, 53 μm, 75 μm or 125 μm, which may be selected according to the particle size requirements for a specific packaging scenario without any particular limitation.

[0066] In the present invention, there is no particular limitation on the specific type of the release agent, which may be a conventional release agent in the art. In some embodiments, the release agent is carnauba wax and / or oxidized polyethylene wax.

[0067] In the present invention, the first coupling agent is a silane coupling agent, which is mainly used as a surface modifier of an inorganic filler. It changes the physical and chemical properties of the surface of the inorganic filler through a chemical reaction or chemical adsorption mechanism, improves the dispersibility of the filler in the resin, and increases the compatibility of the interface between the inorganic filler and the resin, thereby improving the mechanical properties, chemical properties and electrical properties of the EMC. It is preferably one or more of 3-glycidyloxypropyltrimethoxysilane (KH560), 3-mercaptopropyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane and N-phenyl-3-aminopropyltrimethoxysilane.

[0068] In a preferred embodiment, the first coupling agent and the second coupling agent are both 3-glycidyloxypropyltrimethoxysilane (KH560).

[0069] The present invention does not limit the specific selection of the first epoxy resin, and can be conventional epoxy resins in the art to meet specific packaging performance requirements. In some embodiments, the first epoxy resin is selected from one or more of resins such as o-cresol type epoxy resin (EOCN), dicyclopentadiene type epoxy resin (DCPD), phenol biphenyl alkyl type epoxy resin (MAR), trisphenol methane type multifunctional epoxy resin, biphenyl type epoxy resin (BP), naphthol aralkyl type epoxy resin, tetramethyl bisphenol F type epoxy resin, naphthalene ring type epoxy resin, etc., preferably a mixture of o-cresol type epoxy resin and biphenyl type epoxy resin. Further preferably, in the first epoxy resin, the weight ratio of the amount of the o-cresol type epoxy resin and the biphenyl type epoxy resin is 9: 1-5.

[0070] In a preferred embodiment, the first epoxy resin and the second epoxy resin are both a mixture of an o-cresol-formaldehyde epoxy resin and a biphenyl epoxy resin.

[0071] The present invention does not make any particular limitation on the specific type of the curing agent, and can be a conventional curing agent in the art. In some embodiments, the curing agent is a phenolic resin curing agent. Preferably, the curing agent is selected from one or more of resins such as linear phenol phenolic resin (linear phenolic resin, PN), phenol aralkyl resin (Xylok) containing a phenylene skeleton, phenol aralkyl resin (MAR) containing a biphenylene skeleton, trihydroxyphenylmethane type multifunctional phenolic resin (MFN) and naphthol aralkyl type phenolic resin.

[0072] In the present invention, the accelerator is prepared by compounding an imidazole compound and an organophosphorus compound. In a preferred embodiment, in the accelerator, the weight ratio of the organophosphorus compound to the imidazole compound is 3-10:1, specifically, for example, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1 or 10:1.

[0073] The present invention does not limit the specific types of the imidazole compound and the organophosphorus compound, and can be the imidazole compound and the organophosphorus compound used as promoters conventional in the art. In some embodiments, the organophosphorus compound is triphenylphosphine (TPP), and the imidazole compound is 2-phenyl-4-methylimidazole (2P4MZ). In a preferred embodiment, the promoter is a mixture of triphenylphosphine (TPP) and 2-phenyl-4-methylimidazole (2P4MZ).

[0074] In the present invention, the colorant is mainly used to distinguish / mark different types of devices and cover the design of the packaging unit and prevent light transmission, and can contain one or more pigments according to actual needs, without special limitation. In some embodiments, the colorant is carbon black.

[0075] In the present invention, the specific type of the ion capture agent is not particularly limited, and it can be a commonly used ion capture agent in the art to reduce the content of ions in the EMC and improve the electrical performance. In some embodiments, the ion capture agent is hydrotalcite.

[0076] In the present invention, there is no particular limitation on the specific type of the low stress modifier, which can be a low stress modifier commonly used in the art. Specifically, it can be a silicone oil system (such as Dow Corning SF8421EG), a silicone system (such as Dow Corning AY42-119), an epoxidized polybutadiene (such as Japan Daicel PB-3600), a triblock copolymer containing a silicone component (such as Germany Wacker GENIOPERLW35), a carboxyl-terminated nitrile rubber (such as Huntsman CTBN 1300*8 in the United States), and a silicone-modified epoxy resin (such as Shanghai Bohuai W35). By using a low stress modifier, the stress of the system can be reduced, and the warping deformation of the package and the generation of cracks in the package can be further reduced. The low stress modifier can be used alone or in combination of two or more.

[0077] The present invention also proposes a method for preparing the epoxy resin material as described above, which comprises: mixing a hydroxide / epoxy resin mixture, a solid filler, a colorant and an ion capture agent, a first epoxy resin, a curing agent, an accelerator, a release agent, a solid stress modifier and a low stress modifier, and then extruding the mixture, and cooling, crushing and molding the obtained extruded product.

[0078] In a preferred embodiment, when preparing the epoxy resin material, the extrusion is performed in a twin-screw extruder.

[0079] In a preferred embodiment, when preparing the epoxy resin material, the extrusion conditions include: a temperature of 80-140° C., preferably 100-130° C.; and a screw speed of 50-250 rpm, preferably 150-200 rpm.

[0080] In a preferred embodiment, the preparation method of the epoxy resin material specifically comprises the following steps:

[0081] (1) placing a solid filler, a flame retardant and a colorant into a high-speed mixer in sequence, and slowly spraying the first coupling agent into the mixer in a mist form through a high-pressure nozzle within 10 minutes under stirring, and then stopping stirring after continuing to stir for 5 minutes after spraying;

[0082] (2) adding the crushed first epoxy resin and curing agent, the hydroxide / epoxy resin mixture, the accelerator, the release agent, the low stress modifier, and the ion capture agent into a high-speed mixer and starting stirring to obtain a premixed powder;

[0083] (3) Extruding the premixed powder through a twin-screw extruder at a temperature of 130° C. and a screw speed of 170 rpm to obtain an extruded product, cooling, crushing, and magnetic separation to remove magnetic metals, and then pressing the product into a cake material of a specific size, shape, and compression ratio on a cake forming machine.

[0084] The present invention also proposes the use of the epoxy resin material as described above or the epoxy resin material obtained by the method as described above in semiconductor packaging. The continuous molding stability of the epoxy resin material described in the present invention reaches more than 400 molds, the mold and the packaging body surface are not dirty, and there is no problem of mold sticking and cracking, showing good process operability, improving production efficiency, and reducing the cost pressure caused by mold cleaning; at the same time, after the epoxy resin material encapsulates the semiconductor, it can pass the MSL1 delamination and reliability test. Therefore, when the epoxy resin material is used as an epoxy molding compound (EMC) for semiconductor packaging, it has good operability and high reliability.

[0085] The present invention will be described in detail below by way of examples, but the protection scope of the present invention is not limited thereto. The experimental methods in the following examples, unless otherwise specified, are conventional methods in the art. The experimental materials used in the following examples, unless otherwise specified, are all commercially available.

[0086] In the following preparation examples, embodiments and comparative examples:

[0087] A1 (epoxy resin): o-cresol-formaldehyde epoxy resin, purchased from Jinan Shengquan, brand SQCN700-3;

[0088] A2 (epoxy resin): biphenyl epoxy resin, purchased from Mitsubishi, Japan, brand name YX4000;

[0089] Curing agent: linear phenolic resin, purchased from Shanghai Hengfeng, brand name Resicare3010;

[0090] C1 (inorganic filler): crystalline silicon dioxide powder, purchased from Jiangsu Lianrui, brand DC1270B;

[0091] C2 (inorganic filler): fused silica powder, purchased from Jiangsu Lianrui, brand DQ-1200;

[0092] D1 (accelerator): triphenylphosphine, purchased from Hangzhou Ruike, brand name TPP;

[0093] D2 (accelerator): 2-phenyl-4-methylimidazole, purchased from Nanjing Lanbi'an Biochemical Technology Co., Ltd.;

[0094] Low stress modifier: silicone modified epoxy resin, purchased from Shanghai Bohuai, brand W35;

[0095] Coupling agent: purchased from Danyang Duoli, brand KH560;

[0096] Flame retardant: hexaphenoxy cyclotriphosphazene;

[0097] Colorant: carbon black;

[0098] Ion scavenger: hydrotalcite;

[0099] Dispersant: trimethyl stearamide sodium chloride, purchased from East-West Trading Co., Ltd., brand name D-818M;

[0100] Release agent: oxidized polyethylene wax, Clariant, PED522.

[0101] Hydroxide: Aluminum hydroxide, Banglutong, BE033.

[0102] Preparation Examples 1-3 are used to illustrate the preparation of the coupling agent-modified hydroxide / epoxy resin mixture of the present invention.

[0103] Preparation Example 1

[0104] A1. Place 8 kg of hydroxide (aluminum hydroxide) and 1.5 kg of crushed epoxy resin (mixed by ortho-cresol epoxy resin and biphenyl epoxy resin in a mass ratio of 1:1) in a high mixing tank and mix and stir for 3 minutes. During the mixing and stirring process, spray 0.5 kg of coupling agent and 0.1 g of dispersant. Continue stirring for 3 minutes after spraying to obtain a mixed powder.

[0105] A2. Extruding the mixed powder obtained in step A1 through a twin-screw extruder at a temperature of 130° C. and a screw speed of 170 rpm. After the extruded product is cooled, it is crushed to obtain a hydroxide / epoxy resin mixture I modified by a coupling agent under a specific process.

[0106] Preparation Example 2

[0107] A1. 8 kg of hydroxide (aluminum hydroxide) and 1.25 kg of crushed epoxy resin (mixed by ortho-cresol epoxy resin and biphenyl epoxy resin in a mass ratio of 1:1) were placed in a high mixing tank and mixed and stirred for 3 minutes. During the mixing and stirring process, 0.75 kg of coupling agent and 0.01 kg of dispersant were sprayed in. After spraying, stirring was continued for 3 minutes to obtain a mixed powder.

[0108] A2. Extruding the mixed powder obtained in step A1 through a twin-screw extruder at a temperature of 130° C. and a screw speed of 170 rpm, and crushing the extruded product after cooling, thereby obtaining a hydroxide / epoxy resin mixture II modified by a coupling agent under a specific process.

[0109] Preparation Example 3

[0110] A1. 8 kg of hydroxide (aluminum hydroxide) and 1.75 kg of crushed epoxy resin (mixed by ortho-cresol epoxy resin and biphenyl epoxy resin in a mass ratio of 1:1) were placed in a high mixing tank and mixed and stirred for 3 minutes. During the mixing and stirring process, 0.25 kg of coupling agent and 0.01 kg of dispersant were sprayed in. After spraying, stirring was continued for 3 minutes to obtain a mixed powder.

[0111] A2. Extruding the mixed powder obtained in step A1 through a twin-screw extruder at a temperature of 130° C. and a screw speed of 170 rpm. After the extruded product is cooled, it is crushed to obtain a hydroxide / epoxy resin mixture III modified by a coupling agent under a specific process.

[0112] The epoxy resin materials were prepared in the following manner:

[0113] (1) Put the solid filler, flame retardant and colorant into a high-speed mixer in sequence, and slowly spray the coupling agent into the mixer in a mist form through a high-pressure nozzle within 10 minutes under stirring. Continue stirring for 5 minutes after spraying and then stop stirring;

[0114] (2) adding the crushed epoxy resin and curing agent, the hydroxide / epoxy resin mixture, the accelerator, the release agent, the low stress modifier, and the ion capture agent into a high-speed mixer and starting stirring to obtain a premixed powder;

[0115] (3) Extruding the premixed powder through a twin-screw extruder at a temperature of 130° C. and a screw speed of 170 rpm to obtain an extruded product, cooling, crushing, and magnetic separation to remove magnetic metals, and then pressing the product into a cake material of a specific size, shape, and compression ratio on a cake forming machine.

[0116] The raw material formula composition for preparing the epoxy resin material in Examples 1-5 is shown in Table 1 (each component is in parts by weight).

[0117] Table 1

[0118]

[0119] Comparative Example 1

[0120] The method described in Example 3 was followed, except that when preparing the hydroxide / epoxy resin mixture modified by the coupling agent under a specific process, it was mixed in a high mixing tank without extrusion.

[0121] Comparative Example 2

[0122] The method described in Example 3 is used for implementation, except that when preparing the hydroxide / epoxy resin mixture modified by the coupling agent under a specific process, the coupling agent and the dispersant are not sprayed in, and the mixed hydroxide and epoxy resin are directly extruded.

[0123] Comparative Example 3

[0124] The method described in Example 3 is used for implementation, except that when preparing the hydroxide / epoxy resin mixture modified by the coupling agent under a specific process, the dispersant is not sprayed in, and the mixed hydroxide, epoxy resin and coupling agent are directly extruded.

[0125] Comparative Example 4

[0126] The method described in Example 3 is used for implementation, except that when preparing the hydroxide / epoxy resin mixture modified by the coupling agent under a specific process, the coupling agent is not sprayed, and the mixed hydroxide, epoxy resin and dispersant are directly extruded.

[0127] Comparative Example 5

[0128] The method described in Example 3 was followed, except that no accelerator D1 was added when preparing the epoxy resin material (accelerator D1 was replaced with accelerator D2 of equal mass).

[0129] Comparative Example 6

[0130] The method described in Example 3 was followed, except that no accelerator D2 was added when preparing the epoxy resin material (accelerator D2 was replaced with accelerator D1 of equal mass).

[0131] Test Case

[0132] The gel time, fluidity, water absorption, flame retardancy, open mold flexural strength and open mold flexural modulus, glass transition temperature (Tg), storage modulus, thermal expansion coefficient and continuous molding stability of the products prepared in Examples 1-5 and Comparative Examples 1-6 were measured respectively.

[0133] The test method is as follows:

[0134] (1) Gelation time: Heat the hot plate to 175 ± 1 °C, take 2-3 g of sample and place it on the iron plate, stir it continuously with a small needle, and test the time it takes for the sample to change from a fluid to a gel.

[0135] (2) Fluidity: 30 g of sample was measured using a resin transfer injection molding machine with a spiral flow metal mold, and the injection pressure was 70 kgf / cm 2 , the mold temperature is 175±1℃.

[0136] (3) Water absorption rate: The water absorption rate test is carried out according to the "PCT24" method, wherein the sample size is 50 mm*3 mm (diameter*thickness), and the test conditions are 121°C, 100RH%, 2atm, and 24h; the water absorption rate is calculated as follows: weight increase of the sample after PCT24 / initial weight of the sample*100%.

[0137] (4) Flame retardancy: vertical combustion method is used according to GB / T 2408 standard.

[0138] (5) Open mold bending strength and open mold bending modulus: 110g of powdered epoxy resin molding material was put into the injection molding machine. Under the conditions of injection pressure of 60bar and injection time of 15s, the material was injected into a special bending strength test mold at 175℃ to make a 15.41*10.78*120mm sample. After 120s of curing, the resin product was hardened and formed. Within 15s, the heat-cured molded sample was quickly taken out and placed in the test area of ​​the universal testing machine, and the pressure test was started.

[0139] (6) Glass transition temperature (Tg) and storage modulus: The Tg of EMC can be determined by dynamic mechanical analysis (DMA) or thermomechanical analysis (TMA), and the storage modulus is determined by DMA. First, the EMC powder is cured for 150 seconds at a mold temperature of 180°C in a molding machine to make a sample bar / sheet, and then placed in an oven at 180°C for post-curing for 6 hours. The size of the sample block for TMA testing is 5mm*5mm (diameter*thickness); the size of the sample bar for DMA testing is 60mm*13mm*3.2mm (length*width*thickness).

[0140] (7) Thermal expansion coefficient (CTE1 / CTE2): measured using the above-mentioned TMA.

[0141] (8) Continuous molding stability: Take 14*5.5 epoxy resin molding material cake, and inject it at a pressure of 75kg / cm 2 , mold clamping pressure 160kg / cm 2 , and the mold closing time is 120s, and continuous packaging is performed. The surface of the semiconductor device is observed until irregular color difference or dirt appears on the surface, and the number of continuous packaging molds is recorded to characterize the stability of continuous molding.

[0142] (9) MSL1 Moisture Sensitivity Level Test: The semiconductor device encapsulated with epoxy resin molding material cake is cured at 175℃ / 6H and electroplated and then tested as follows:

[0143] Initial inspection: SAT layer scan to confirm there is no delamination;

[0144] Initial electrical inspection;

[0145] Baking: Bake at 125℃ for 24 hours to completely remove moisture;

[0146] Moisture absorption: Moisture absorption treatment was carried out according to the treatment conditions of MSL1 (85°C / 85%RH, 168h);

[0147] Reflow: IR-Reflow at 255℃±5 for three times;

[0148] Final inspection: SAT layer scanning to confirm whether there is delamination;

[0149] Final electrical test.

[0150] During the final inspection, if there is no delamination in the SAT scan and no leakage or short circuit abnormalities in the electrical inspection, it can be determined that it has passed the MSL1 moisture sensitivity level test.

[0151] The MSL1 moisture sensitivity level test results of the epoxy resin molding materials prepared in Examples 1-5 and Comparative Examples 1-6 are shown in Table 2.

[0152] The gel time, fluidity, water absorption, flame retardancy, mold opening bending strength and mold opening bending modulus, glass transition temperature (Tg), storage modulus, thermal expansion coefficient, DMA modulus and other results of the epoxy resin molding materials prepared in Examples 1-5 and Comparative Examples 1-6 are shown in Table 3; It should be noted that since Comparative Examples 5-6 could not pass the MSL1 test, their continuous molding stability was not tested on the client side. According to the corresponding laboratory data, it is estimated that the continuous molding stability of Comparative Examples 5-6 is about 245 to 260 molds.

[0153] Table 2

[0154]

[0155]

[0156] Table 3

[0157]

[0158] As can be seen from Table 2 and Table 3, the epoxy resin materials prepared in Examples 1-5 of the present invention have a lower storage modulus at 260°C and can pass the moisture sensitivity level MSL1 test, showing high reliability. The present invention designs the raw material components and uses extrusion to modify aluminum hydroxide on the basis of dry modification, so that the prepared epoxy resin material can pass the moisture sensitivity level MSL1 test and has a longer continuous molding stability. After 400 continuous encapsulations, the product surface still maintains a uniform state and has high operability.

[0159] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. An epoxy resin material, characterized in that: The epoxy resin material comprises a first epoxy resin, a curing agent, an ion capture agent, a low stress modifier, a first coupling agent, an accelerator, a colorant, a flame retardant, a release agent, a hydroxide / epoxy resin mixture and a solid filler; Wherein, the hydroxide / epoxy resin mixture is obtained by mixing hydroxide, a second epoxy resin, a second coupling agent and a dispersant, and then extruding; the second coupling agent is a silane coupling agent; The accelerator is a mixture of an imidazole compound and an organic phosphorus compound.

2. The epoxy resin material according to claim 1, characterized in that: The hydroxide / epoxy resin mixture is prepared according to the following steps: A1. Stir and mix the hydroxide and the second epoxy resin, add the second coupling agent and the dispersant during the stirring process, and continue stirring to obtain a mixed powder; A2. Extruding the mixed powder.

3. The epoxy resin material according to claim 1 or 2, characterized in that: The weight ratio of the hydroxide, the second epoxy resin, the silane coupling agent and the dispersant is 80:4-35:0.9-11:0.08-1.1; and / or The second coupling agent is selected from one or more of 3-glycidyloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and N-phenyl-3-aminopropyltrimethoxysilane; and / or The second epoxy resin is selected from one or more of o-cresol type epoxy resin, dicyclopentadiene type epoxy resin, phenol biphenyl alkyl type epoxy resin, trisphenol methane type multifunctional epoxy resin, biphenyl type epoxy resin, naphthol aralkyl type epoxy resin, tetramethyl bisphenol F type epoxy resin and naphthalene ring type epoxy resin, preferably o-cresol type epoxy resin and biphenyl type epoxy resin; and / or, The dispersant is selected from one or more of trimethyl stearamide chloride, alkyl aryl phosphate and alkyl benzene sulfonate; and / or The hydroxide is selected from aluminum hydroxide and / or magnesium hydroxide.

4. The epoxy resin material according to claim 1 or 2, characterized in that: The extrusion is carried out in a twin-screw extruder; and / or The extrusion conditions include: a temperature of 80-140° C. and a screw speed of 50-250 rpm.

5. The epoxy resin material according to claim 2, characterized in that: Before step A1, the method further includes: crushing the second epoxy resin; and / or In step A1, the stirring and mixing time is 3-10 min; and / or In step A1, the stirring time is continued for 3-10 minutes.

6. The epoxy resin material according to any one of claims 1 to 5, characterized in that: Based on the total weight of the epoxy resin material as 100 weight %, the content of the first epoxy resin is 8-15 weight %, the content of the curing agent is 3-8 weight %, the content of the ion capture agent is 0.1-1 weight %, the content of the low stress modifier is 0.01-1 weight %, the content of the first coupling agent is 0.2-1.5 weight %, the content of the accelerator is 0.1-1 weight %, the content of the colorant is 0.1-1 weight %, the content of the flame retardant is 0.1-5 weight %, the content of the release agent is 0.1-1 weight %, the content of the hydroxide / epoxy resin mixture is 1-25 weight %, and the content of the solid filler is 50-85 weight %.

7. The epoxy resin material according to claim 1 or 6, characterized in that: The flame retardant is a non-hydroxide flame retardant; and / or The solid filler is a non-hydroxide solid filler; and / or The first coupling agent is a silane coupling agent; and / or The first epoxy resin is selected from one or more of o-cresol type epoxy resin, dicyclopentadiene type epoxy resin, phenol biphenyl alkyl type epoxy resin, trisphenol methane type multifunctional epoxy resin, biphenyl type epoxy resin, naphthol aralkyl type epoxy resin, tetramethyl bisphenol F type epoxy resin and naphthalene ring type epoxy resin, preferably a mixture of o-cresol type epoxy resin and biphenyl type epoxy resin; and / or The curing agent is a phenolic resin curing agent.

8. The epoxy resin material according to claim 1 or 7, characterized in that: The flame retardant is selected from one or more of halogen flame retardants, phosphorus flame retardants, nitrogen flame retardants, phosphorus-halogen flame retardants and phosphorus-nitrogen flame retardants; and / or The solid filler is selected from one or more of crystalline silica, fused silica, alumina and metal nitride, preferably a mixture of crystalline silica and fused silica; and / or The first coupling agent is selected from one or more of 3-glycidyloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and N-phenyl-3-aminopropyltrimethoxysilane; and / or The curing agent is one or more selected from linear phenolic resin, phenol aralkyl resin containing a phenylene skeleton, phenol aralkyl resin containing a biphenylene skeleton, trihydroxyphenylmethane type multifunctional phenolic resin and naphthol aralkyl type phenolic resin; and / or The accelerator is a mixture of triphenylphosphine and 2-phenyl-4-methylimidazole.

9. A method for preparing the epoxy resin material according to any one of claims 1 to 8, characterized in that: The method comprises: mixing a hydroxide / epoxy resin mixture, a solid filler, a colorant and an ion capture agent, a first epoxy resin, a curing agent, an accelerator, a release agent, a solid stress modifier and a low stress modifier, and then extruding the mixture, and cooling, crushing and molding the obtained extruded product; Preferably, a twin-screw extruder is used for extrusion; Preferably, the extrusion conditions include: a temperature of 80-140° C. and a screw speed of 50-250 rpm.

10. Use of the epoxy resin material according to any one of claims 1 to 8 or the epoxy resin material prepared by the method according to claim 9 in semiconductor packaging.

Images