Liquid epoxy resin composition, method for producing the same, and use thereof

Abstract

This invention discloses a liquid epoxy resin composition, its preparation method, and its application. By mass percentage, its raw material composition is: 78%-93% modified inorganic filler, 2%-10% alicyclic epoxy resin, 0.5%-5% aromatic epoxy resin, 2-15% curing agent, 0.1-2% adhesion accelerator, 0.1-1% curing accelerator, 0.5-5% stress absorber, and 0.2-5% flame retardant; the modified inorganic filler is a C5-C20 coupling agent modified inorganic filler. The preparation method includes the following steps: first, the alicyclic epoxy resin, aromatic epoxy resin, stress absorber, flame retardant, adhesion accelerator, and curing agent are uniformly mixed at room temperature; the mixture obtained above is then thoroughly mixed with the modified inorganic filler at 25-45°C and cooled to room temperature; finally, the curing accelerator is added and mixed uniformly to obtain the liquid epoxy resin composition. The liquid epoxy composition provided by this invention not only has a high glass transition temperature and a low coefficient of thermal expansion, but also features low warpage, making it suitable for integrated circuit packaging.

Description

Technical Field

[0001] This invention belongs to the field of integrated circuit electronic packaging technology, and relates to a low-stress, low-warpage liquid epoxy resin composition, its preparation method and application. Background Technology

[0002] In recent years, with the continuous development of integrated circuits, electronic packaging has gradually shifted towards lower costs, thinner profiles, smaller sizes, lighter weights, higher performance, and higher integration. Among these, wafer-level packaging involves manipulating the wafer for most of the packaging process before dicing it into individual chips. Molding is a crucial step, often using liquid epoxy resin compositions for compression molding, simultaneously encapsulating the entire wafer and monolithically adding chips, thus significantly improving production efficiency and reducing production costs.

[0003] However, wafers encapsulated in wafer-level packaging are prone to warping, which in turn affects the yield of subsequent processes such as grinding, dicing, and assembly. Wafer warping mainly stems from stress issues: encapsulating a large surface area of ​​the wafer makes it susceptible to warping due to differences in thermal expansion coefficients, elastic moduli, and shrinkage rates between the molding compound and the wafer support. Summary of the Invention

[0004] In order to solve the problems mentioned in the background art, the present invention aims to provide a low-stress, low-warpage liquid epoxy resin composition, its preparation method and application, wherein the liquid epoxy resin composition not only has a high glass transition temperature and a low coefficient of thermal expansion, but also has the characteristics of low warpage deformation.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: On one hand, the present invention provides a liquid epoxy resin composition, the raw material composition of which, by mass percentage, is:

[0006] Modified inorganic filler 78%-93%, alicyclic epoxy resin 2%-10%, aromatic ring-containing epoxy resin 0.5%-5%, curing agent 2-15%, adhesion promoter 0.1-2%, curing accelerator 0.1-1%, stress absorber 0.5-5%, and flame retardant 0.2-5%;

[0007] The aromatic ring-containing epoxy resin is an epoxy resin whose molecular chain contains an aromatic ring.

[0008] The modified inorganic filler is an inorganic filler modified with C5-C20 coupling agent.

[0009] Furthermore, its raw material composition, by mass percentage, is as follows:

[0010] The composition includes 80%-90% modified inorganic filler, 3%-10% alicyclic epoxy resin, 0.5-5% aromatic ring-containing epoxy resin, 3-10% curing agent, 0.1-1% adhesion accelerator, 0.1-0.5% curing accelerator, 0.5-2% stress absorber, and 0.2-5% flame retardant.

[0011] Furthermore, the modified inorganic filler is an inorganic filler modified with a silane coupling agent containing an olefin chain with C5-C20 carbon atoms;

[0012] Preferably, the modified inorganic filler is an inorganic filler modified with a silane coupling agent containing an olefin chain with 10-18 carbon atoms;

[0013] Preferably, the modified inorganic filler is an inorganic filler modified with a silane coupling agent containing an olefin chain with 10-16 carbon atoms.

[0014] Furthermore, the inorganic filler is silicon dioxide;

[0015] Preferably, the C5-C20 coupling agent modified silica is obtained by the following steps: adding unmodified silica to a high-speed mixer, adding 3.0-5.0% C5-C20 coupling agent by weight of the silica raw material by spraying, stirring at high speed for 60-120 minutes, drying at 60-90°C for 3-5 hours after discharge, and then cooling to obtain C5-C20 coupling agent modified silica.

[0016] Furthermore, the modified inorganic filler is spherical in shape, and the average particle size of the modified inorganic filler is 1-50 μm, preferably 10-30 μm.

[0017] Furthermore, the molecular weight of the alicyclic epoxy resin is 500-10000;

[0018] Preferably, the alicyclic epoxy resin comprises one or a combination of at least two of the following: 1,2-epoxy-4-vinylcyclohexane, 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexylcarboxylate, bis(7-oxabicyclo[4.1.0]3-heptylmethyl) adipate, methyl 3,4-epoxycyclohexanecarboxylate, 4,5-epoxycyclohexane-1,2-dicarboxylic acid diglycidyl ester, and 1,4-cyclohexanediethanol bis(3,4-epoxycyclohexanecarboxylate).

[0019] Furthermore, the aromatic ring-containing epoxy resin includes one or a combination of at least two of the following: bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, biphenyl-type epoxy resin, bisphenol AD ​​epoxy resin, p-hydroxybenzoic acid, diglycidyl aniline, 1,1,2,2-tetra(p-hydroxyphenyl)ethane tetraglycidyl ether epoxy resin, and p-aminophenol triglycidyl epoxy resin.

[0020] Furthermore, the curing agent is selected from one or a combination of at least two of the following: liquid anhydrides, phenols, alicyclic amines, aromatic amines, naphthyl phenolic resins and their derivatives, and copolymers of dicyclopentadiene and phenol.

[0021] Preferably, the adhesion promoter is selected from one or a combination of at least two of γ-(2,3-epoxypropoxy)propyltrimethoxysilane, propyl glycidyl ether trimethoxysilane, γ-epoxypropyl ether trimethoxysilane, trimethoxysilane, γ-aminopropyltriethoxysilane, and γ-mercaptopropyltrimethoxysilane.

[0022] Preferably, the curing accelerator is selected from one or a combination of two of imidazole compounds and triphenylphosphine; more preferably, the imidazole compound is selected from one or a combination of at least two of 2-phenyl-4,5-dihydroxymethylimidazolium, 2-methylimidazolium, 2-phenylimidazolium, dimethyl-imidazolium triisocyanate, triphenylphosphine, and triphenylphosphine-1,4-benzoquinone adduct.

[0023] Preferably, the stress absorber is selected from one or a combination of at least two of nitrile rubber, polysulfide rubber, polybutadiene, polyether elastomer, and polyurethane;

[0024] Preferably, the flame retardant is an environmentally friendly flame retardant; more preferably, the flame retardant is selected from one or a combination of at least two of aluminum hydroxide, magnesium hydroxide, antimony trioxide, melamine, polysiloxane, and phosphate ester.

[0025] On the other hand, the present invention provides a method for preparing any of the above-mentioned liquid epoxy resin compositions, comprising the following steps: firstly, uniformly mixing alicyclic epoxy resin, aromatic epoxy resin, stress absorber, flame retardant, adhesion promoter, and curing agent at room temperature; then, fully mixing the mixture obtained above with modified inorganic filler at 25-45°C and cooling it to room temperature; and finally, adding curing promoter and mixing uniformly to obtain the liquid epoxy resin composition.

[0026] On the other hand, the present invention provides an application of any of the above-described liquid epoxy resin compositions in integrated circuit packaging.

[0027] The beneficial effects of this invention are as follows: The liquid epoxy resin composition provided by this invention, through the addition of inorganic fillers modified with C5-C20 coupling agents (preferably inorganic fillers modified with C10-C16 coupling agents; carbon chains that are too short have poor wettability with the resin, while carbon chains that are too long will lead to a decrease in the Tg of the resin composition), gives the resin system excellent flexibility, which can improve warpage, and good compatibility with epoxy resin. Simultaneously, the addition of aromatic ring epoxy resin containing rigid chains gives the resin system good thermal stability. The modified inorganic filler has a mass fraction of over 78%, and the high filler content results in a low CTE, which can effectively reduce the coefficient of thermal expansion and thus suppress the warpage of semiconductor wafers. The liquid epoxy resin composition provided by this invention not only has a high glass transition temperature and a low coefficient of thermal expansion, but also features low warpage deformation. Detailed Implementation

[0028] To better understand the content of this invention, the following detailed description is provided in conjunction with specific implementation methods. However, the scope of protection of this invention is not limited to the following embodiments.

[0029] Example 1

[0030] The composition of the liquid epoxy resin composition is shown in the table below:

[0031]

[0032]

[0033] Modified inorganic fillers are prepared by the following methods:

[0034] Unmodified silica filler with an average particle size of 25 μm was added to a high-speed mixer. Dodecyltriethoxysilane, accounting for 3.0-5.0% of the raw material weight, was added to the silica raw material by spraying. The mixture was stirred at high speed for 60 min. After discharge, the material was dried at 80°C for 3-5 hours and then cooled.

[0035] The liquid epoxy resin composition was prepared by the following method:

[0036] First, epoxy resin, stress absorber, flame retardant, adhesion accelerator, and curing agent are mixed uniformly at room temperature. The mixture obtained above is then thoroughly mixed with inorganic filler at 35°C and cooled to room temperature. Finally, curing accelerator is added and mixed uniformly to obtain a liquid epoxy resin composition.

[0037] Warpage evaluation: On a 750 μm thick, 300 mm diameter wafer, a sealing resin composition was compressed for 5 minutes at 5 MPa and 125 °C using a TOWA compression molding machine to obtain an encapsulation material with a thickness of 500 μm. The prepared compression-molded sample was cured at 150 °C for 2 hours to obtain samples for warpage testing.

[0038] Evaluation of coefficient of thermal expansion and glass transition temperature (Tg): Cured products with dimensions of 3 mm × 3 mm × 5 mm were measured using a TMA402 thermometer manufactured by NETZSCH. Measurements were taken at a heating rate of 5 °C / min from 0 °C to 260 °C. The coefficient of thermal expansion (ppm / °C) between 25 °C and 75 °C is defined as CTE1, and the coefficient of thermal expansion (ppm / °C) between 190 °C and 240 °C is defined as CTE2. The intersection of the two tangents is defined as Tg.

[0039] In this embodiment, the liquid epoxy resin composition has a Tg of 150°C, a thermal expansion coefficient CTE1 of 15ppm / K, a CTE2 of 55ppm / K, and a warpage of 1mm.

[0040] Example 2

[0041] The composition of the liquid epoxy resin composition is shown in the table below:

[0042] Components mass percentage / % Epoxy resin: 1,2-epoxy-4-vinylcyclohexane 4.00％ Epoxy resin: Biphenyl type epoxy resin 3.00％ Curing agent: acid anhydride curing agent 7.50％ Inorganic packing: Modified inorganic packing 83.00％ Adhesion accelerator: Propyl glycidyl ether trimethoxysilane 0.20％ Curing accelerator: triphenylphosphine 0.50％ Stress absorber: Nitrile rubber 0.80％ Flame retardant: magnesium hydroxide 1.00％

[0043] Modified inorganic fillers are prepared by the following methods:

[0044] Unmodified silica filler with an average particle size of 25 μm was added to a high-speed mixer. Hexadecyltrimethoxysilane, accounting for 3.0-5.0% of the raw material weight, was added to the silica raw material by spraying. The mixture was stirred at high speed for 60 min. After discharge, the material was dried at 80°C for 3-5 hours and then cooled.

[0045] Preparation of liquid epoxy resin composition: An epoxy resin composition was prepared according to the method in Example 1 to obtain a sample.

[0046] In this embodiment, the liquid epoxy resin composition has a Tg of 143°C, a coefficient of thermal expansion CTE1 of 16ppm / K, a CTE2 of 56ppm / K, and a warpage of 1.1mm.

[0047] Example 3

[0048] The composition of the liquid epoxy resin composition is shown in the table below:

[0049] Components mass percentage / % Epoxy resin: 1,2-epoxy-4-vinylcyclohexane 2.10％ Epoxy resin: Bisphenol A epoxy resin 1.90％ Curing agent: acid anhydride curing agent 3.90％ Inorganic packing: Modified inorganic packing 90.00％ Adhesion accelerator: Propyl glycidyl ether trimethoxysilane 0.30％ Curing accelerator: 2-Phenylimidazole 0.50％ Stress absorber: Nitrile rubber 0.80％ Flame retardant: magnesium hydroxide 0.50％

[0050] Preparation of modified inorganic fillers: Prepared according to the method in Example 1;

[0051] Preparation of liquid epoxy resin composition: An epoxy resin composition was prepared according to the method in Example 1 to obtain a sample.

[0052] In this embodiment, the liquid epoxy resin composition has a Tg of 160°C, a coefficient of thermal expansion CTE1 of 8 ppm / K, a CTE2 of 45 ppm / K, and a warpage of 0.9 mm.

[0053] Example 4

[0054] The composition of the liquid epoxy resin composition is shown in the table below:

[0055]

[0056]

[0057] Modified inorganic fillers are prepared by the following methods:

[0058] Unmodified silica filler with an average particle size of 25 μm was added to a high-speed mixer. Hexadecyltrimethoxysilane, accounting for 3.0-5.0% of the raw material weight, was added to the silica raw material by spraying. The mixture was stirred at high speed for 60 min. After discharge, the material was dried at 80°C for 3-5 hours and then cooled.

[0059] Preparation of liquid epoxy resin composition: An epoxy resin composition was prepared according to the method in Example 1 to obtain a sample.

[0060] In this embodiment, the liquid epoxy resin composition has a Tg of 140°C, a coefficient of thermal expansion CTE1 of 13ppm / K, a CTE2 of 50ppm / K, and a warpage of 1.1mm.

[0061] Example 5

[0062] The composition of the liquid epoxy resin composition is shown in the table below:

[0063] Components mass percentage / % Epoxy resin: 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexyl carboxylate 4.00％ Epoxy resin: Bisphenol A epoxy resin 1.50％ Curing agent: Biphenyl-type phenolic resin 5.00％ Inorganic packing: Modified inorganic packing 86.50％ Adhesion accelerator: γ-glycidyl ether trimethoxysilane 0.50％ Curing accelerator: 2-methylimidazole 0.50％ Stress absorber: polybutadiene 1.00％ Flame retardant: magnesium hydroxide 1.00％

[0064] Modified inorganic fillers are prepared by the following methods:

[0065] Unmodified silica filler with an average particle size of 25 μm was added to a high-speed mixer. Octadecyltrimethoxysilane, accounting for 3.0-5.0% of the raw material weight, was added to the silica raw material by spraying. The mixture was stirred at high speed for 60 min. After discharge, the material was dried at 80°C for 3-5 hours and then cooled.

[0066] Preparation of liquid epoxy resin composition: An epoxy resin composition was prepared according to the method in Example 1 to obtain a sample.

[0067] In this embodiment, the liquid epoxy resin composition has a Tg of 148°C, a coefficient of thermal expansion CTE1 of 13ppm / K, a CTE2 of 50ppm / K, and a warpage of 1.0mm.

[0068] Comparative Example 1

[0069] The composition of the liquid epoxy resin composition is shown in the table below:

[0070]

[0071] Preparation of liquid epoxy resin composition: An epoxy resin composition was prepared according to the method in Example 1 to obtain a sample.

[0072] In this embodiment, the liquid epoxy resin composition has a Tg of 148°C, a coefficient of thermal expansion CTE1 of 15ppm / K, a CTE2 of 55ppm / K, and a warpage of 1.3mm.

[0073] Comparative Example 2

[0074] The composition of the liquid epoxy resin composition is shown in the table below:

[0075] Components mass percentage / % Epoxy resin: 1,2-epoxy-4-vinylcyclohexane 7.00％ Curing agent: acid anhydride curing agent 7.50％ Inorganic filler: molten silica 83.00％ Adhesion accelerator: Propyl glycidyl ether trimethoxysilane 0.20％ Curing accelerator: triphenylphosphine 0.50％ Stress absorber: Nitrile rubber 0.80％ Flame retardant: magnesium hydroxide 1.00％

[0076] Preparation of liquid epoxy resin composition: An epoxy resin composition was prepared according to the method in Example 1 to obtain a sample.

[0077] In this embodiment, the liquid epoxy resin composition has a Tg of 146°C, a coefficient of thermal expansion CTE1 of 18 ppm / K, a CTE2 of 58 ppm / K, and a warpage of 1.3 mm.

[0078] Comparative Example 3

[0079] The composition of the liquid epoxy resin composition is shown in the table below:

[0080]

[0081]

[0082] Modified inorganic fillers are prepared by the following methods:

[0083] Unmodified silica filler was added to a high-speed mixer. The average particle size of the silica was 25 μm. Vinyltrimethoxysilane, accounting for 3.0-5.0% of the weight of the silica raw material, was added to the silica raw material by spraying. The mixture was stirred at high speed for 60 min. After discharge, the material was dried at 80°C for 3-5 hours and then cooled.

[0084] Preparation of liquid epoxy resin composition: An epoxy resin composition was prepared according to the method in Example 1 to obtain a sample.

[0085] In this embodiment, the liquid epoxy resin composition has a Tg of 150°C, a coefficient of thermal expansion CTE1 of 18ppm / K, a CTE2 of 58ppm / K, and a warpage of 1.5mm.

[0086] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the inventive concept, and all such modifications and substitutions should be considered to fall within the patent protection scope defined by the claims submitted herein.

Claims

1. A liquid epoxy resin composition, characterized by comprising: Its raw material composition, by mass percentage, is as follows: The composition includes 78%-93% modified inorganic filler, 2%-10% alicyclic epoxy resin, 0.5%-5% aromatic ring-containing epoxy resin, 2-15% curing agent, 0.1-2% adhesion accelerator, 0.1-1% curing accelerator, 0.5-5% stress absorber, and 0.2-5% flame retardant. The aromatic ring-containing epoxy resin is an epoxy resin whose molecular chain contains an aromatic ring. The modified inorganic filler is C10-C20 silane coupling agent modified silica, and the average particle size of the modified inorganic filler is 1 μm to 50 μm. The C10-C20 silane coupling agent modified silica is obtained through the following steps: unmodified silica is added to a high-speed mixer, and 3.0-5.0% of C10-C20 silane coupling agent by weight of the raw material is added to the silica raw material by spraying. The mixture is stirred at high speed for 60-120 minutes, and after discharge, it is dried at 60-90°C for 3-5 hours and then cooled to obtain C10-C20 silane coupling agent modified silica.

2. The liquid epoxy resin composition according to claim 1, characterized by Its raw material composition, by mass percentage, is as follows: The composition includes 80%-90% modified inorganic filler, 3%-10% alicyclic epoxy resin, 0.5-5% aromatic ring-containing epoxy resin, 3-10% curing agent, 0.1-1% adhesion promoter, 0.1-0.5% curing accelerator, 0.5-2% stress absorber, and 0.2-5% flame retardant.

3. The liquid epoxy resin composition according to claim 1, wherein The modified inorganic filler is silicon dioxide modified with a silane coupling agent containing 10-18 carbon atoms.

4. The liquid epoxy resin composition according to claim 1, wherein The modified inorganic filler is spherical in shape, and the average particle size of the modified inorganic filler is 10-30 μm.

5. The liquid epoxy resin composition according to claim 1, wherein The molecular weight of the alicyclic epoxy resin is 500-10000; The alicyclic epoxy resin includes one or a combination of at least two of the following: 1,2-epoxy-4-vinylcyclohexane, 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexylcarboxylate, bis(7-oxabicyclo[4.1.0]3-heptylmethyl) adipate, methyl 3,4-epoxycyclohexanecarboxylate, 4,5-epoxycyclohexane-1,2-dicarboxylic acid diglycidyl ester, and 1,4-cyclohexanediethanol bis(3,4-epoxycyclohexanecarboxylate).

6. The liquid epoxy resin composition according to claim 1, wherein The aromatic ring-containing epoxy resin includes one or a combination of at least two of the following: bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, biphenyl-type epoxy resin, bisphenol AD ​​epoxy resin, 1,1,2,2-tetra(p-hydroxyphenyl)ethane tetraglycidyl ether epoxy resin, and p-aminophenol triglycidyl epoxy resin.

7. The liquid epoxy resin composition according to claim 1, wherein The curing agent is selected from one or a combination of at least two of the following: liquid anhydrides, phenols, alicyclic amines, aromatic amines, naphthyl phenolic resins and their derivatives, and copolymers of dicyclopentadiene and phenol. The adhesion promoter is selected from one or a combination of at least two of γ-(2,3-epoxypropoxy)propyltrimethoxysilane, propyl glycidyl ether trimethoxysilane, γ-epoxypropyl ether trimethoxysilane, trimethoxysilane, γ-aminopropyltriethoxysilane, and γ-mercaptopropyltrimethoxysilane. The curing accelerator is selected from one or a combination of two of imidazole compounds and triphenylphosphine. The stress absorber is selected from one or a combination of at least two of nitrile rubber, polysulfide rubber, polybutadiene, polyether elastomer, and polyurethane; The flame retardant is an environmentally friendly flame retardant, selected from one or a combination of at least two of aluminum hydroxide, magnesium hydroxide, antimony trioxide, melamine, polysiloxane, and phosphate ester.

8. The liquid epoxy resin composition according to claim 7, wherein The imidazole compound is selected from one or a combination of at least two of 2-phenyl-4,5-dihydroxymethylimidazolium, 2-methylimidazolium, 2-phenylimidazolium, and dimethylimidazolium triisocyanate.

9. The method of producing the liquid epoxy resin composition according to any one of claims 1 to 8, characterized by, The process includes the following steps: First, alicyclic epoxy resin, aromatic epoxy resin, stress absorber, flame retardant, adhesion promoter, and curing agent are uniformly mixed at room temperature. The mixture obtained above is then fully mixed with modified inorganic filler at 25-45°C and cooled to room temperature. Finally, a curing promoter is added and mixed evenly to obtain a liquid epoxy resin composition.

10. The use of the liquid epoxy resin composition according to any one of claims 1-8 in integrated circuit packaging.