Additive film for FC-BGA encapsulation substrate containing negative thermal expansion material, its preparation method and application

Abstract

This invention provides an extension film for FC-BGA encapsulation substrates containing a negative thermal expansion material, its preparation method, and its application. The extension film comprises the following components in parts by weight: 50-60 parts epoxy resin, 5-10 parts phenoxy resin, 30-35 parts curing agent, 70-80 parts inorganic filler, and 10-20 parts phase change negative thermal expansion material. The preparation method includes the following steps: mixing the components of the extension film evenly, coating it onto a substrate, and drying to obtain the extension film. By using inorganic filler and a phase change negative thermal expansion material, this invention produces an extension film with a low coefficient of thermal expansion, suitable for preparing FC-BGA encapsulation substrates.

Description

Technical Field

[0001] This invention belongs to the field of resin composite material technology, specifically relating to the lamination film for FC-BGA encapsulation carrier containing negative thermal expansion material, its preparation method, and its application. Background Technology

[0002] Flip-chip ball grid array (FC-BGA) substrates represent the future direction of semiconductor packaging substrates, with wide applications and a promising market prospect. FC-BGA packaging substrates are high-density packaging substrates capable of enabling high-speed and multifunctional chips. Additive films are one of the key materials in the SAP (Semi-Additive Processing) manufacturing process of FC-BGA substrates. However, the thermal expansion of the resin system in existing additive films generates thermal stress. Excessive thermal stress can damage the reliability of the FC-BGA packaging substrate and its packaging system. Furthermore, mismatch in the coefficient of thermal expansion can easily cause via cracks and delamination failures. In addition, additive films not only need good physical properties but also controllable thermal expansion properties to improve the dimensional stability of the material structure and extend its service life.

[0003] Therefore, how to control the coefficient of thermal expansion of the laminate film, avoid substrate warping and encapsulation structure failure caused by thermal expansion and coefficient of thermal expansion mismatch, eliminate defects caused by material thermal expansion, and achieve controllable thermal expansion performance of the laminate film for FC-BGA encapsulation substrate has become an urgent technical problem to be solved. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide an extension film for FC-BGA encapsulation substrates containing a negative thermal expansion material, its preparation method, and its applications. By designing the composition of the extension film, based on components such as epoxy resin, phenoxy resin, and curing agent, and through the use of inorganic fillers and a phase change negative thermal expansion material, the present invention produces an extension film with a low coefficient of thermal expansion, suitable for preparing FC-BGA encapsulation substrates.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] In a first aspect, the present invention provides an additive film for FC-BGA encapsulation substrates containing a negative thermal expansion material, the additive film comprising the following components in parts by weight:

[0007] 50-60 parts epoxy resin, 5-10 parts phenoxy resin, 30-35 parts curing agent, 70-80 parts inorganic filler, and 10-20 parts phase change negative thermal expansion material.

[0008] In this invention, by designing the composition of the laminated film, based on components such as epoxy resin, phenoxy resin, and curing agent, and by using inorganic fillers and phase change negative thermal expansion materials, the laminated film prepared has a low coefficient of thermal expansion and is suitable for preparing FC-BGA packaging substrates.

[0009] Phase change negative thermal expansion materials are compounds with anomalous thermal expansion properties, characterized by a negative coefficient of thermal expansion. They can be combined with other positive thermal expansion materials to regulate the thermal expansion properties of the matrix material. In this invention, by using inorganic fillers and phase change negative thermal expansion materials in combination, and further by reacting the inorganic fillers with epoxy groups to construct an interconnected network structure, the movement of epoxy resin molecular chain segments is restricted, the coefficient of thermal expansion of the system is reduced, and defects caused by material thermal expansion are eliminated. This achieves controllable thermal expansion properties of the laminated adhesive film for FC-BGA encapsulation substrates.

[0010] In this invention, by controlling the amount of phase change negative thermal expansion material within a specific range, a laminated film with controllable thermal expansion properties can be obtained. If the amount of phase change negative thermal expansion material is too small, the thermal expansion phenomenon cannot be effectively reduced, and the coefficient of thermal expansion of the laminated film is large; if the amount of phase change negative thermal expansion material is too large, due to the poor compatibility between the negative thermal expansion material and the system, it is easy to precipitate, resulting in the inability to form a film.

[0011] In this invention, the weight percentage of epoxy resin in the laminated film can be 50 parts, 51 parts, 52 parts, 53 parts, 54 parts, 55 parts, 56 parts, 57 parts, 58 parts, 59 parts, or 60 parts, etc.

[0012] The weight parts of phenoxy resin can be 5 parts, 5.5 parts, 6 parts, 6.5 parts, 7 parts, 7.5 parts, 8 parts, 8.5 parts, 9 parts, 9.5 parts, or 10 parts, etc.

[0013] The weight percentage of the curing agent can be 30, 31, 32, 33, 34, or 35 parts, etc.

[0014] The weight percentages of the inorganic filler can be 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, or 80 parts, etc.

[0015] The weight percentages of the phase change negative thermal expansion material can be 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 parts, etc.

[0016] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. The purpose and beneficial effects of the present invention can be better achieved and realized through the following preferred technical solutions.

[0017] As a preferred embodiment of the present invention, the particle size of the phase change negative thermal expansion material is 200-300nm, for example, it can be 200nm, 210nm, 220nm, 230nm, 240nm, 250nm, 260nm, 270nm, 280nm, 290nm or 300nm, etc.

[0018] Preferably, the phase change negative thermal expansion material is selected from any one or a combination of at least two of zinc pyrophosphate, lead titanate, or barium titanate.

[0019] The reason for the negative thermal expansion phenomenon in phase change negative thermal expansion materials is that as the temperature increases, the structure changes from one type to another, i.e., a structural phase transition occurs. The symmetry of the polyhedron also changes, becoming lower and the cell volume smaller. As the temperature increases, the repulsive force between cations in the phase transition temperature range decreases, and the polyhedral distortion also decreases. This causes the crystal lattice to exhibit positive thermal expansion properties in some directions and contraction in others, resulting in an overall contraction of the total lattice volume and thus negative thermal expansion. In this invention, phase change negative thermal expansion materials with a particle size of 100-300 nm are used. Smaller particle sizes of negative thermal expansion materials have a better modification effect on the polymer matrix, allowing for thorough blending of the negative thermal expansion filler with the positive thermal expansion matrix. This increases the interfacial force between the negative and positive thermal expansion components, and through mutual cancellation, the film achieves controllable thermal expansion properties.

[0020] As a preferred embodiment of the present invention, the inorganic filler is selected from any one or a combination of at least two of the following: silicon dioxide, clay, alumina, glass, cordierite, aluminum hydroxide, magnesium hydroxide, boron nitride, or aluminum nitride.

[0021] Preferably, the particle size of the inorganic filler is 500-800 nm, for example, it can be 500 nm, 520 nm, 550 nm, 570 nm, 600 nm, 630 nm, 660 nm, 680 nm, 700 nm, 720 nm, 750 nm, 780 nm or 800 nm.

[0022] Preferably, the silicon dioxide is mercapto-modified silicon dioxide.

[0023] In this invention, mercapto-modified silica can form thiols under the action of amino compounds such as N,N-dimethylformamide, 4-dimethylaminopyridine, and aminated clay, thereby promoting the reaction between epoxy groups and mercapto groups to generate secondary hydroxyl groups and thioether bonds, increasing the packing density of the molecular chain and silica. The denser the packing, the smaller the free volume, and the restricted space for movement of epoxy resin molecular chain segments, thus obtaining good thermal expansion properties.

[0024] Preferably, the raw materials for preparing the thiolized silica include silica and a thiolizing agent.

[0025] Preferably, the mass ratio of silicon dioxide to mercapto reagent is 100:(4-8), for example, it can be 100:4, 100:4.5, 100:5, 100:5.5, 100:6, 100:6.5, 100:7, 100:7.5 or 100:8, etc.

[0026] Preferably, the thiolation agent comprises 3-mercaptopropyltriethoxysilane.

[0027] Preferably, the mercaptolated silica is prepared by the following method, which includes the following steps:

[0028] Silica and a mercapto reagent are dispersed in solvent A and subjected to a modification reaction to obtain the mercapto-modified silica.

[0029] Preferably, solvent A is selected from ethanol and / or water, and more preferably a combination of ethanol and water.

[0030] Preferably, the modification reaction is carried out in the presence of ammonia.

[0031] It should be noted that the present invention does not impose any special restrictions on the specific amounts of solvent and ammonia, which can be added as needed.

[0032] Preferably, the temperature of the modification reaction is 25-40℃ (e.g., 25℃, 27℃, 30℃, 32℃, 34℃, 36℃, 38℃, or 40℃, etc.), and the time of the modification reaction is 20-30h (e.g., 20h, 21h, 22h, 23h, 24h, 25h, 26h, 27h, 28h, 29h, or 30h, etc.).

[0033] Preferably, the modification reaction further includes a post-processing step, the post-processing method including centrifugation, washing, and drying.

[0034] Preferably, the mercaptolated silica is prepared by the following method, which specifically includes the following steps:

[0035] Mix anhydrous ethanol (80-100 mL), deionized water (15-20 mL), and ammonia (5-8 mL) in a constant temperature water bath at 25-40℃ for 10-15 min to ensure uniform mixing. Weigh 5 mg of silica and add it to the mixture. Continue stirring at a constant speed in a constant temperature water bath at 25-40℃. Add 0.02-0.04 g of thiolizing agent to the system and react for 20-30 h. Centrifuge at 10000-120000 r / min for 3-5 min to obtain the solid. Wash the solid twice with 50% ethanol solution and centrifuge twice, then wash it twice with anhydrous ethanol and centrifuge twice. Disperse the obtained solid by ultrasonication and dry it to obtain thiolized silica.

[0036] Preferably, the clay is aminated clay.

[0037] Clay particles are rigid, and their uniform dispersion in a matrix creates a large surface area, hindering the expansion of polymer chains at high temperatures and leading to a decrease in the material's coefficient of thermal expansion. In this invention, the clay particles undergo amylation surface modification treatment. Through the reaction of amino and epoxy groups, the compatibility between the clay and the resin matrix is ​​improved, the dispersibility of the clay particles in the resin matrix is ​​enhanced, and an interconnected network structure is constructed. This restricts the movement of epoxy resin molecular chain segments and reduces the system's coefficient of thermal expansion.

[0038] Preferably, the raw materials for preparing the amination clay include clay and an amination reagent.

[0039] Preferably, the mass ratio of the clay to the amination reagent is 1:(1.2-1.8), for example, it can be 1:1.2, 1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7 or 1:1.8, etc.

[0040] Preferably, the aminated clay is prepared by the following method, which includes the following steps:

[0041] Clay, amination reagent and solvent B are mixed and reacted to obtain the amination clay.

[0042] Preferably, solvent B is selected from any one or a combination of at least two of ethanol, isopropanol, or butanol.

[0043] It should be noted that there are no special restrictions on the amount of solvent used in this invention, and it can be added as needed.

[0044] Preferably, the reaction time is 20-30 hours, for example, 20 hours, 21 hours, 22 hours, 23 hours, 24 hours, 25 hours, 26 hours, 27 hours, 28 hours, 29 hours, or 30 hours.

[0045] Preferably, the reaction further includes a post-processing step, the post-processing method including: centrifugation, washing, drying, and grinding.

[0046] The aminated clay is prepared by the following method, which specifically includes the following steps:

[0047] Add 10g of clay and 12-18g of amination reagent to an ethanol solution (200-250mL) at room temperature, stir and react for 20-30h, then centrifuge. Wash the precipitate with ethanol, centrifuge three times, and then dry it in a drying oven at 35-45℃ for 10-15h. Grind the dried product into powder in a mortar to obtain amino clay.

[0048] As a preferred embodiment of the present invention, the inorganic filler is selected from mercapto-hydrated silica and / or aminated clay, preferably a combination of mercapto-hydrated silica and aminated clay.

[0049] Preferably, the mass ratio of the mercaptolated silica to the aminated clay is (3-4):1, for example, it can be 3:1, 3.1:1, 3.2:1, 3.3:1, 3.4:1, 3.5:1, 3.6:1, 3.7:1, 3.8:1, 3.9:1 or 4:1, etc.

[0050] In this invention, by selecting a combination of mercapto-modified silica and aminated clay, and further controlling the mass ratio of mercapto-modified silica to aminated clay within a specific range, the coefficient of thermal expansion of the laminated film can be further reduced, and the overall performance of the laminated film can be improved. If the mass ratio of mercapto-modified silica to aminated clay is too small, excessive aminated clay in the laminated film is prone to agglomeration, resulting in poor dispersion and poor film formation. If the mass ratio of mercapto-modified silica to aminated clay is too large, the number of amino groups in the laminated film is relatively reduced, decreasing the efficiency of mercapto-modified silica in forming thiol ions, which is detrimental to the reaction between epoxy groups and mercapto groups.

[0051] As a preferred embodiment of the present invention, the epoxy resin is selected from any one or a combination of at least two of the following: bisphenol type epoxy resin, biphenyl type epoxy resin, phenol type epoxy resin, naphthol type epoxy resin, linear phenolic epoxy resin, dicyclopentadiene type epoxy resin, aralkyl type phenolic epoxy resin, aralkyl biphenyl type phenolic epoxy resin, or naphthol type phenolic epoxy resin.

[0052] Preferably, the curing agent is selected from any one or a combination of at least two of the following: reactive ester curing agent, carbodiimide curing agent, phenol curing agent, naphthol curing agent, cyanate ester curing agent, and benzoxazine curing agent.

[0053] As a preferred embodiment of the present invention, the laminated film further includes 0.1 to 0.5 parts by weight of a curing accelerator, such as 0.1, 0.2, 0.3, 0.4, or 0.5 parts by weight.

[0054] Preferably, the curing accelerator is selected from any one or a combination of at least two of 1-cyanoethyl-2-ethyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-ethyl-4-methylimidazole, 4-dimethylaminopyridine, and 2-phenylimidazole.

[0055] Preferably, the thickening film further includes 3 to 9 parts by weight of an additive, for example, 3 parts by weight, 4 parts by weight, 5 parts by weight, 6 parts by weight, 7 parts by weight, 8 parts by weight or 9 parts by weight.

[0056] Preferably, the additive is selected from any one or a combination of at least two of the following: thickener, defoamer, homogenizer, leveling agent, adhesion promoter, and colorant.

[0057] It should be noted that there are no special restrictions on the specific selection of thickeners, defoamers, homogenizers, leveling agents, adhesion promoters and colorants in this invention, and the above-mentioned additives commonly used in the art are all applicable.

[0058] Preferably, the thickening film further includes 200 to 300 parts by weight of organic solvent, such as 200 parts by weight, 210 parts by weight, 220 parts by weight, 230 parts by weight, 240 parts by weight, 250 parts by weight, 260 parts by weight, 270 parts by weight, 280 parts by weight, 290 parts by weight, or 300 parts by weight.

[0059] Preferably, the organic solvent is selected from any one or a combination of at least two of toluene, xylene, butanone, methyl ethyl ketone, cyclohexanone, ethyl acetate, or N,N-dimethylformamide.

[0060] As a preferred embodiment of the present invention, the thickness of the laminated film is 10 to 100 μm, for example, it can be 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm or 100 μm.

[0061] In a second aspect, the present invention provides a method for preparing the laminated film as described in the first aspect, the method comprising the following steps:

[0062] After the components of the laminate film are mixed evenly, they are coated onto the substrate and dried to obtain the laminate film.

[0063] As a preferred embodiment of the present invention, the thickness of the substrate is 10-150 μm (for example, it can be 10 μm, 25 μm, 40 μm, 500 μm, 75 μm, 100 μm, 120 μm, 140 μm or 150 μm, etc.), and more preferably 25-50 μm.

[0064] Preferably, the drying temperature is 80-130°C, for example, it can be 80°C, 85°C, 90°C, 95°C, 100°C, 105°C, 110°C, 115°C, 120°C, 125°C or 130°C.

[0065] Preferably, the drying time is 3 to 10 minutes, for example, 3 minutes, 4 minutes, 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes or 10 minutes.

[0066] Preferably, the drying process further includes a post-processing step.

[0067] Preferably, the post-processing method is to remove the substrate.

[0068] Preferably, the preparation method specifically includes the following steps:

[0069] After the components of the laminated adhesive film are mixed evenly, the mixture is coated onto a substrate and dried at 80–130°C for 3–10 minutes. The substrate is then removed to obtain the laminated adhesive film.

[0070] Thirdly, the present invention provides an application of the laminated adhesive film as described in the first aspect in an FC-BGA packaging substrate.

[0071] Compared with the prior art, the present invention has the following beneficial effects:

[0072] In this invention, the composition of the laminated film is designed, and the combination of phase change negative thermal expansion material, mercaptoized silica and aminated clay is used. The amount of phase change negative thermal expansion material and the mass ratio of mercaptoized silica and aminated clay are controlled within a specific range. The resulting laminated film is easy to form, has controllable thermal expansion properties and excellent performance. Its coefficient of thermal expansion is 18-20 ppm / ℃ and its warpage height is 0.7-0.9 mm. Detailed Implementation

[0073] To facilitate understanding of the present invention, the following embodiments are provided. Those skilled in the art should understand that these embodiments are merely illustrative and should not be construed as limiting the scope of the invention.

[0074] The sources of some components in the following preparation examples, embodiments, and comparative examples are as follows:

[0075] Silicon dioxide: CAS No. 7631-86-9;

[0076] Clay: CAS No. 1340-68-7;

[0077] Alumina: CAS No. 11092-32-3;

[0078] Aluminum hydroxide: CAS No. 21645-51-2;

[0079] Zinc pyrophosphate: CAS No. 7446-26-6;

[0080] Lead titanate: CAS No. 12060-00-3;

[0081] Barium titanate: CAS No. 12047-27-7;

[0082] Epoxy resins: 25 parts of bisphenol A type epoxy resin ("828US" manufactured by Mitsubishi Chemical Co., Ltd., Japan), biphenyl type epoxy resin ("NC3000L" manufactured by Nippon Kayaku Co., Ltd.), and biphenyl aralkyl type epoxy resin ("YX4000HK" manufactured by Mitsubishi Chemical Co., Ltd., Japan).

[0083] Phenoxy resin: "YL7553BH30" manufactured by Mitsubishi Chemical Co., Ltd., Japan;

[0084] Curing agents: reactive ester curing agent (“HPC-8000-65T” manufactured by DIC Corporation), carbodiimide curing agent (“V-03” manufactured by Nisshinbo Chemical Co., Ltd.), phenol curing agent (“LA-3018-50P” manufactured by Meiwa Kasei Co., Ltd., Japan).

[0085] Preparation Example 1

[0086] This preparation example provides a mercapto-modified silica and its preparation method, the preparation method being as follows:

[0087] Mix 80 mL of anhydrous ethanol, 15 mL of deionized water, and 5 mL of ammonia in a 35°C water bath for 10 min to ensure homogeneity. Weigh 5 mg of silica and add it to the mixture. Continue stirring at a constant speed in a 35°C water bath. Add 0.25 mL of 3-mercaptopropyltriethoxysilane to the system and react for 24 h. Centrifuge at 10000 r / min for 5 min to obtain the solid. Wash the solid twice with 50% ethanol solution and centrifuge twice, then wash it twice with anhydrous ethanol. Disperse the solid by ultrasonication and dry it for later use to obtain mercapto-modified silica.

[0088] Preparation Example 2

[0089] This preparation example provides an aminated clay and its preparation method, the preparation method being as follows:

[0090] Add 10g of clay and 15mL of 3-aminopropyltriethoxysilane to 200mL of ethanol solution at room temperature, stir for 24h, and centrifuge. Wash the precipitate with ethanol, centrifuge three times, and then dry it in a drying oven at 40℃ for 12h. Grind the dried product into powder in a mortar to obtain amino clay.

[0091] The thiolized silica mentioned in the following examples and comparative examples are all the thiolized silica provided in Preparation Example 1 above, and the aminated clay mentioned are all the aminated clay provided in Preparation Example 2 above.

[0092] Example 1

[0093] This embodiment provides an additive film and its preparation method, wherein the additive film comprises the following components in parts by weight:

[0094] 10 parts of bisphenol A type epoxy resin (828US), 25 parts of biphenyl type epoxy resin (NC3000L), 25 parts of biphenyl aralkyl type epoxy resin (YX4000HK), 6 parts of phenoxy resin (YL7553BH30), 13 parts of reactive ester curing agent (HPC-8000-65T), 10 parts of carbodiimide curing agent (V-03), 7.5 parts of phenol curing agent (LA-3018-50P), 75 parts of inorganic filler, 15 parts of zinc pyrophosphate, 0.3 parts of 4-dimethylaminopyridine (DMAP), 6 parts of leveling agent, and 300 parts of cyclohexanone;

[0095] The inorganic filler is composed of mercapto-modified silica and aminated clay in a mass ratio of 3.5:1.

[0096] The preparation method of the above-mentioned thickened adhesive film is as follows:

[0097] After the components of the laminate film are mixed evenly, they are coated onto the substrate and dried at 100°C for 5 minutes. The substrate is then removed to obtain a laminate film with a thickness of 50 μm.

[0098] Example 2

[0099] This embodiment provides an additive film and its preparation method, wherein the additive film comprises the following components in parts by weight:

[0100] 10 parts of bisphenol A type epoxy resin (828US), 20 parts of biphenyl type epoxy resin (NC3000L), 20 parts of biphenyl aralkyl type epoxy resin (YX4000HK), 10 parts of phenoxy resin, 13 parts of reactive ester curing agent (HPC-8000-65T), 10 parts of carbodiimide curing agent (V-03), 7 parts of phenol curing agent (LA-3018-50P), 80 parts of inorganic filler, 10 parts of lead titanate, 0.3 parts of 4-dimethylaminopyridine, 5 parts of leveling agent, and 200 parts of N,N-dimethylformamide;

[0101] The inorganic filler is composed of mercapto-modified silica and aminated clay in a mass ratio of 3:1.

[0102] The preparation method of the above-mentioned thickened adhesive film is as follows:

[0103] After the components of the laminate film are mixed evenly, they are coated onto the substrate and dried at 80°C for 10 minutes. The substrate is then removed to obtain a laminate film with a thickness of 10 μm.

[0104] Example 3

[0105] This embodiment provides an additive film and its preparation method, wherein the additive film comprises the following components in parts by weight:

[0106] 8 parts of bisphenol A type epoxy resin (828US), 25 parts of biphenyl type epoxy resin (NC3000L), 25 parts of biphenyl aralkyl type epoxy resin (YX4000HK), 5 parts of phenoxy resin, 15 parts of reactive ester curing agent (HPC-8000-65T), 10 parts of carbodiimide curing agent (V-03), 10 parts of phenol curing agent (LA-3018-50P), 70 parts of inorganic filler, 18 parts of barium titanate, 0.5 parts of 4-dimethylaminopyridine, 9 parts of leveling agent, and 300 parts of toluene;

[0107] The inorganic filler is composed of mercapto-modified silica and aminated clay in a mass ratio of 11:3.

[0108] The preparation method of the above-mentioned thickened adhesive film is as follows:

[0109] After the components of the laminated film are mixed evenly, they are coated onto the substrate and dried at 130°C for 3 minutes. The substrate is then removed to obtain a laminated film with a thickness of 100 μm.

[0110] Example 4

[0111] This embodiment provides a layered adhesive film and its preparation method. The only difference from Embodiment 1 is that, under the premise that the total amount of inorganic filler remains unchanged, the inorganic filler is composed of mercapto-modified silica and aminated clay in a mass ratio of 3:1. Other conditions are the same as in Embodiment 1.

[0112] Example 5

[0113] This embodiment provides a layered adhesive film and its preparation method. The only difference from Embodiment 1 is that, under the premise that the total amount of inorganic filler remains unchanged, the inorganic filler is composed of mercapto-modified silica and aminated clay in a mass ratio of 4:1. Other conditions are the same as in Embodiment 1.

[0114] Example 6

[0115] This embodiment provides a layered adhesive film and its preparation method. The only difference from Embodiment 1 is that, under the premise that the total amount of inorganic filler remains unchanged, the inorganic filler is composed of mercapto-modified silica and aminated clay in a mass ratio of 2.4:1. Other conditions are the same as in Embodiment 1.

[0116] Example 7

[0117] This embodiment provides a layered adhesive film and its preparation method. The only difference from Embodiment 1 is that, under the premise that the total amount of inorganic filler remains unchanged, the inorganic filler is composed of mercapto-modified silica and aminated clay in a mass ratio of 5:1. Other conditions are the same as in Embodiment 1.

[0118] Example 8

[0119] This embodiment provides a layered adhesive film and its preparation method. The only difference from Embodiment 1 is that, under the premise that the total amount of inorganic filler remains unchanged, only mercaptoized silica is used as the inorganic filler. Other conditions are the same as in Embodiment 1.

[0120] Example 9

[0121] This embodiment provides a layered adhesive film and its preparation method. The only difference from Embodiment 1 is that, under the premise that the total amount of inorganic filler remains unchanged, only aminated clay is used as the inorganic filler. Other conditions are the same as in Embodiment 1.

[0122] Example 10

[0123] This embodiment provides a layered adhesive film and its preparation method. The only difference from Embodiment 1 is that, under the premise that the total amount of inorganic filler remains unchanged, the inorganic filler is composed of silica and clay in a mass ratio of 3.5:1. Other conditions are the same as in Embodiment 1.

[0124] Example 11

[0125] This embodiment provides a layered adhesive film and its preparation method. The only difference from Embodiment 1 is that the weight of the phase change negative thermal expansion material in the layered adhesive film is 10 parts, and the other conditions are the same as in Embodiment 1.

[0126] Example 12

[0127] This embodiment provides a layered adhesive film and its preparation method. The only difference from Embodiment 1 is that the weight of the phase change negative thermal expansion material in the layered adhesive film is 20 parts, and the other conditions are the same as in Embodiment 1.

[0128] Comparative Example 1

[0129] This comparative example provides a layered adhesive film and its preparation method. The only difference from Example 1 is that the weight of the phase change negative thermal expansion material in the layered adhesive film is 8 parts, and the other conditions are the same as in Example 1.

[0130] Comparative Example 2

[0131] This comparative example provides a layered adhesive film and its preparation method. The only difference from Example 1 is that the weight of the phase change negative thermal expansion material in the layered adhesive film is 24 parts, and the other conditions are the same as in Example 1.

[0132] Comparative Example 3

[0133] This comparative example provides a laminated adhesive film and its preparation method. The only difference from Example 1 is that the laminated adhesive film does not contain phase change negative thermal expansion material, and the weight of inorganic filler is 90 parts. Other conditions are the same as in Example 1.

[0134] Comparative Example 4

[0135] This comparative example provides a layered adhesive film and its preparation method. The only difference from Example 1 is that the layered adhesive film does not contain inorganic fillers, and the weight of the phase change negative thermal expansion material is 90 parts. Other conditions are the same as in Example 1.

[0136] The performance of the laminated films provided in the above embodiments and comparative examples was tested, and the specific test methods are as follows:

[0137] Coefficient of thermal expansion: The PET release film-coated adhesive film provided in the above examples and comparative examples was cured at 100°C for 30 min and at 190°C for 90 min. Then the release film was peeled off to obtain the test sample. The test sample was cut into test pieces with a width of about 3 mm and a length of about 120 mm. Thermomechanical analysis was performed using a thermomechanical analysis device (TA Instruments' "TMA450") under the conditions of a preload force of 0.02 N, a heating range of 25°C to 260°C, and a heating rate of 10°C / min to obtain the coefficient of thermal expansion in the range of 25°C to 150°C.

[0138] Warpage height evaluation: The PET release film reinforcement film provided in the above examples and comparative examples was cut into 300×300mm samples, and pressed onto 35μm copper foil using a vacuum laminator. The samples were cured at 100℃ for 30min and at 190℃ for 90min. Then the release film was peeled off, and the samples were placed horizontally on a flat marble tabletop. The maximum warpage value was observed, and the unit was mm.

[0139] Film-forming properties: Mix all components of the laminated adhesive film evenly, and use a coating machine to quickly and evenly coat it onto a substrate such as PET release film in both longitudinal and transverse directions to form a uniform adhesive film without any gaps or overflows. If the film is uniform, it is considered to be able to form a film; otherwise, it is considered to be unable to form a film.

[0140] The performance test results of the laminated films provided in the above embodiments and comparative examples are shown in the table below:

[0141] Table 1

[0142] Film-forming properties Coefficient of thermal expansion (ppm / ℃) Warpage height (mm) Example 1 Film-forming 19 0.8 Example 2 Film-forming 18 0.7 Example 3 Film-forming 19 0.9 Example 4 Film-forming 19 0.7 Example 5 Film-forming 18 0.8 Example 6 Non-film-forming - - Example 7 Film-forming 26 1.7 Example 8 Film-forming 28 1.9 Example 9 Non-film-forming - - Example 10 Film-forming 35 2.7 Example 11 Film-forming 20 0.9 Example 12 Film-forming 18 0.7 Comparative Example 1 Film-forming 25 1.5 Comparative Example 2 Non-film-forming - - Comparative Example 3 Film-forming 33 2.4 Comparative Example 4 Non-film-forming - -

[0143] As can be seen from the above, by designing the composition of the laminated film in this invention, and by using a combination of phase change negative thermal expansion material, mercaptoized silica, and aminated clay, and by controlling the amount of phase change negative thermal expansion material and the mass ratio of mercaptoized silica and aminated clay within a specific range, the laminated film prepared is easy to form, has controllable thermal expansion properties, and excellent performance. Its coefficient of thermal expansion is 18-20 ppm / ℃, and its warpage height is 0.7-0.9 mm.

[0144] Compared with Example 1, if the mass ratio of mercaptosilica to aminated clay is too small (Example 6), a film cannot be formed; if the mass ratio of mercaptosilica to aminated clay is too large (Example 7), the coefficient of thermal expansion of the prepared laminated film is larger.

[0145] Compared with Example 1, if only mercapto-modified silica is used as an inorganic filler to prepare the thickened film (Example 8), the coefficient of thermal expansion of the prepared thickened film is larger; if only aminated clay is used as an inorganic filler to prepare the thickened film (Example 9), the film cannot be formed.

[0146] Compared with Example 1, if unmodified inorganic fillers are used to prepare the thickened film (Example 10), the coefficient of thermal expansion of the prepared thickened film is larger.

[0147] Compared with Example 1, if the amount of phase change negative thermal expansion material is too small (Comparative Example 1), the coefficient of thermal expansion of the prepared laminated film is larger; if the amount of phase change negative thermal expansion material is too large (Comparative Example 2), film cannot be formed.

[0148] Compared with Example 1, if the thickened film does not contain a phase change negative thermal expansion material (Comparative Example 3), the coefficient of thermal expansion of the prepared thickened film is too large and the warpage height is high; if the thickened film does not contain inorganic fillers (Comparative Example 4), it cannot be formed.

[0149] In summary, the present invention designs the composition of the laminated film, uses a combination of phase change negative thermal expansion material, mercaptoized silica and / or aminated clay, controls the amount of phase change negative thermal expansion material within a specific range, and controls the mass ratio of mercaptoized silica and aminated clay within a specific range, thus preparing a laminated film with controllable thermal expansion properties and excellent performance.

[0150] The applicant declares that the detailed process flow of this invention is illustrated by the above embodiments, but this invention is not limited to the above detailed process flow, that is, it does not mean that this invention must rely on the above detailed process flow to be implemented. Those skilled in the art should understand that any improvements to this invention, equivalent substitutions of raw materials for the product of this invention, addition of auxiliary components, and selection of specific methods, etc., all fall within the protection scope and disclosure scope of this invention.

Claims

1. A build-up film for FC-BGA package substrate containing a negative thermal expansion material, characterized by, The build-up adhesive film comprises components in the following weight proportions: epoxy resin 50-60 parts, phenoxy resin 5-10 parts, curing agent 30-35 parts, inorganic filler 70-80 parts, and phase change negative thermal expansion material 10-20 parts; The inorganic filler is a combination of mercapto-silica and amino-clay; The mass ratio of the mercapto-silica and the amino-clay is (3-4):1; The phase change negative thermal expansion material is selected from any one or a combination of at least two of zinc pyrophosphate, lead titanate, or barium titanate.

2. The build-up film according to claim 1, wherein The phase change negative thermal expansion material has a particle size of 200-300 nm.

3. The build-up film according to claim 1, wherein The inorganic filler has a particle size of 500-800 nm.

4. The build tape of claim 1, wherein, The preparation raw material of the mercapto-silica comprises silica and mercapto-reagent.

5. The build tape of claim 4, wherein, The mass ratio of the silica and the mercapto-reagent is 100:(4-8).

6. The build tape of claim 4, wherein, The mercapto-reagent comprises 3-mercaptopropyl triethoxysilane.

7. The build tape of claim 4, wherein, The mercapto-silica is prepared by a method comprising the following steps: The silica and the mercapto-reagent are dispersed in solvent A to perform a modification reaction to obtain the mercapto-silica.

8. The build tape of claim 7, wherein, The solvent A is selected from ethanol and / or water.

9. The build tape of claim 7, wherein, The modification reaction is performed in the presence of ammonia water.

10. The build-up film according to claim 7, wherein The modification reaction is performed at a temperature of 25-40℃ for a time of 20-30 h.

11. The build-up film according to claim 7, wherein The modification reaction further comprises a post-treatment step, and the post-treatment method comprises centrifugation, washing, and drying.

12. The build tape of claim 1, wherein, The preparation raw material of the amino-clay comprises clay and amino-reagent.

13. The build tape of claim 12, wherein, The mass ratio of the clay and the amino-reagent is 1:(1.2-1.8).

14. The build tape of claim 12, wherein, The amino-clay is prepared by a method comprising the following steps: The clay, the amino-reagent, and solvent B are mixed to perform a reaction to obtain the amino-clay.

15. The build tape of claim 14, wherein, The solvent B is selected from any one or a combination of at least two of ethanol, isopropyl alcohol, or butanol.

16. The build tape of claim 14, wherein, The reaction is performed for a time of 20-30 h.

17. The build tape of claim 14, wherein, The reaction further comprises a post-treatment step, and the post-treatment method comprises centrifugation, washing, drying, and grinding.

18. The build tape of claim 1, wherein, The epoxy resin is selected from any one or a combination of at least two of bisphenol-type epoxy resin, biphenyl-type epoxy resin, phenol-type epoxy resin, naphthol-type epoxy resin, linear phenolic-type epoxy resin, dicyclopentadiene-type epoxy resin, aralkyl-type phenolic epoxy resin, aralkyl biphenyl-type phenolic epoxy resin, or naphthol-type phenolic epoxy resin.

19. The build tape of claim 1, wherein, The curing agent is selected from any one or a combination of at least two of active ester curing agent, carbodiimide curing agent, phenol curing agent, naphthol curing agent, cyanate ester curing agent, and benzoxazine curing agent.

20. The build tape of claim 1, wherein, The build-up adhesive film further comprises a curing accelerator in an amount of 0.1-0.5 parts by weight.

21. The build tape of claim 20, wherein, The curing accelerator is selected from any one or a combination of at least two of 1-cyanoethyl-2-ethyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-ethyl-4-methylimidazole, 4-dimethylaminopyridine, and 2-phenylimidazole.

22. The build tape of claim 1, wherein, The build-up adhesive film further comprises an auxiliary agent in an amount of 3-9 parts by weight.

23. The build tape of claim 22, wherein, The auxiliary agent is selected from any one or a combination of at least two of a thickening agent, an antifoaming agent, a leveling agent, a coalescing agent, a colorant, and a colorant.

24. The build tape of claim 1, wherein, The build-up film further comprises 200 to 300 parts by weight of an organic solvent.

25. The build tape of claim 24, wherein, The organic solvent is selected from any one or a combination of at least two of toluene, xylene, butanone, methyl ethyl ketone, cyclohexanone, ethyl acetate, and N,N-dimethylformamide.

26. The build tape of claim 1, wherein, The build-up film has a thickness of 10 to 100 μm.

27. A method of preparing a build tape according to any one of claims 1 to 26, characterised in that, The preparation method comprises the following steps: After the components of the build-up film are mixed uniformly, the build-up film is coated on a substrate, dried, and the build-up film is obtained.

28. The method of claim 27, wherein, The substrate has a thickness of 10 to 150 μm.

29. The method of claim 28, wherein, The substrate has a thickness of 25 to 50 μm.

30. The preparation method according to claim 27, characterized in that, The drying temperature is 80 to 130 °C.

31. The preparation method according to claim 27, characterized in that, The drying time is 3 to 10 min.

32. The preparation method according to claim 27, characterized in that, The drying further comprises a post-treatment step.

33. The method of claim 32, wherein the method further comprises, The post-treatment method is to remove the substrate.

34. Use of the build-up film according to any one of claims 1 to 26 in an FC-BGA package carrier.