Build-up adhesive film for flame-retardant FC-BGA packaging substrate, preparation method therefor, and use thereof

Abstract

Disclosed are a build-up adhesive film for a flame-retardant FC-BGA packaging substrate, a preparation method therefor, and a use thereof, said film comprising, in parts by weight: 30-40 parts of an epoxy resin; 20-25 parts of a curing agent; 1-3 parts of a phenoxy resin; 0.05-0.1 parts of a curing accelerator; 80-100 parts of an inorganic filler, the inorganic filler being selected from one or two of modified boron nitride nanotubes and modified silica; the curing agent comprises a phosphorus-containing cyanate. The present invention uses the curing agent and the inorganic filler to form a composite flame retardant system on the basis of the epoxy resin, the phenoxy resin, the curing accelerator and other components to ensure the application of the build-up adhesive film in FC-BGA packaging substrates; the curing agent uses a phosphorus-containing cyanate, and when it burns, the phosphorus-containing group generates a phosphaphenanthrene group in the gas phase, which can form a stable structure and provide a free radical quenching function; in addition, the nitrogen-containing structure can also obtain a hindered amine structure having a quenching effect, forming a non-flammable gas, providing a gas phase dilution function, and effectively improving the flame retardant effectiveness of the build-up adhesive film.

Description

A flame-retardant FC-BGA package carrier build-up adhesive film and its preparation method and application Technical Field

[0001] The present invention relates to the technical field of resin composite materials, and in particular to a flame-retardant build-up adhesive film for FC-BGA package carrier boards, and a preparation method and application thereof. Background Art

[0002] Flip-chip ball grid array (FC-BGA) substrates feature ultra-high precision and ultra-high density, and are primarily used in large-scale integrated circuit packaging applications such as CPUs and GPUs. Currently, they are the most advanced IC packaging substrates. However, due to the high number of layers, large area, and high circuit density of FC-BGA substrates, their processing is far more difficult than that of conventional packaging substrates, placing high demands on the primary raw material, build-up films. Thermal expansion of the resin system in existing build-up films can generate thermal stress. Excessive thermal stress can undermine the reliability of the FC-BGA substrate and its packaging system. Furthermore, build-up films are primarily composed of flammable polymer materials, which release large amounts of smoke and toxic gases during combustion. Therefore, enhancing the flame retardancy of polymer materials has become a key area of ​​focus for build-up films.

[0003] Therefore, how to reduce the thermal expansion coefficient of the build-up film and thus reduce the warping of the package carrier while ensuring that the build-up film has good flame retardant properties and improving the reliability of the product in practical applications has become a technical problem that needs to be solved urgently.

[0004] Therefore, the existing technology still needs to be improved and developed.

[0005] Summary of the Invention

[0006] In view of the above-mentioned deficiencies in the prior art, the object of the present invention is to provide a flame-retardant build-up adhesive film for FC-BGA package carrier and its preparation method and application, aiming to solve the problem of poor flame retardancy of the existing build-up adhesive film.

[0007] The technical solutions adopted by the present invention to solve the above technical problems are as follows:

[0008] A flame-retardant build-up adhesive film for FC-BGA package carrier, comprising, by weight:

[0009] Wherein, the curing agent includes phosphorus-containing cyanate.

[0010] The flame-retardant FC-BGA package carrier build-up adhesive film, wherein the inorganic filler is selected from one or both of modified boron nitride nanotubes and modified silicon dioxide; the modified boron nitride nanotubes are hydroxylated boron nitride nanotubes; and the modified silicon dioxide is carboxylated silicon dioxide.

[0011] The flame-retardant FC-BGA package carrier build-up adhesive film, wherein the curing agent further includes one or more of a maleimide curing agent, a phenolic curing agent, an active ester curing agent, a carbodiimide curing agent, a phenol curing agent, a naphthol curing agent, and a benzoxazine curing agent.

[0012] The flame-retardant FC-BGA package carrier build-up adhesive film, wherein the phosphorus-containing cyanate ester is selected from one or more of phosphorus-containing cyanate ester I, phosphorus-containing cyanate ester II, phosphorus-containing cyanate ester III and phosphorus-containing cyanate ester IV; wherein the structural formula of the phosphorus-containing cyanate ester I is:

[0013] The structural formula of the phosphorus-containing cyanate II is:

[0014] The structural formula of the phosphorus-containing cyanate III is:

[0015] The structural formula of the phosphorus-containing cyanate IV is:

[0016] The flame-retardant FC-BGA package carrier build-up adhesive film, wherein the epoxy resin is selected from one or more of bisphenol epoxy resin, biphenyl epoxy resin, naphthalene epoxy resin, naphthol epoxy resin, linear phenolic epoxy resin, dicyclopentadiene epoxy resin, aralkyl phenolic epoxy resin, aralkyl biphenyl phenolic epoxy resin, and naphthol phenolic epoxy resin; and the curing accelerator is selected from one or more 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.

[0017] The flame-retardant build-up adhesive film for FC-BGA package carrier board further comprises 3 to 9 parts of an auxiliary agent and / or 200 to 300 parts of an organic solvent.

[0018] The flame-retardant FC-BGA package carrier build-up adhesive film, wherein the auxiliary agent is selected from one or more of a thickener, a defoamer, a leveling agent, a leveling agent, an adhesion-imparting agent, and a colorant; and the organic solvent is selected from one or more of toluene, xylene, butanone, methyl ethyl ketone, cyclohexanone, ethyl acetate, and N,N-dimethylformamide.

[0019] A method for preparing a flame-retardant build-up adhesive film for a FC-BGA package carrier according to the above embodiment of the present invention comprises the following steps:

[0020] Provide epoxy resin, curing agent, phenoxy resin, curing accelerator, inorganic filler;

[0021] The epoxy resin, curing agent, phenoxy resin, curing accelerator and inorganic filler are mixed, coated on a substrate and dried to obtain the flame-retardant FC-BGA package carrier build-up adhesive film.

[0022] In the method for preparing the flame-retardant FC-BGA package carrier build-up adhesive film, the thickness of the substrate is 10 to 150 μm; the drying temperature is 80 to 130° C., and the drying time is 3 to 10 minutes.

[0023] An application of the flame-retardant build-up adhesive film for FC-BGA package carrier according to the above solution of the present invention in FC-BGA package carrier.

[0024] Beneficial effects: The present invention discloses a flame-retardant build-up adhesive film for FC-BGA package carrier boards, and a preparation method and application thereof. On the basis of components such as epoxy resin, phenoxy resin, and curing accelerator, a curing agent is selected and combined with an inorganic filler to form a composite flame retardant system to ensure the application of the build-up adhesive film in FC-BGA package carrier boards; the curing agent is a phosphorus-containing cyanate, and when it burns, the phosphorus-based group will generate a phosphaphenanthrene group in the gas phase, which can capture the free radicals of the gas-phase cracking gas to form a stable structure and exert a free radical quenching effect; at the same time, the nitrogen-containing structure can also obtain a hindered amine structure with a quenching effect, forming a non-flammable gas, which exerts a gas-phase dilution effect. The two can cooperate with each other in the gas phase to effectively improve the flame retardant efficiency of the build-up adhesive film. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] FIG1 is a flow chart of a preferred embodiment of a method for preparing a flame-retardant build-up adhesive film for a FC-BGA package carrier provided by the present invention. DETAILED DESCRIPTION

[0026] The present invention provides a flame-retardant build-up adhesive film for FC-BGA package carriers, as well as a preparation method and application thereof. To further clarify the objectives, technical solutions, and effects of the present invention, the present invention is further described below with reference to the accompanying drawings and examples. It should be understood that the specific examples described herein are intended only to illustrate the present invention and are not intended to limit the present invention.

[0027] It will be understood by those skilled in the art that, unless otherwise stated, the singular forms "a", "an", "said" and "the" used herein may also include plural forms. It should be further understood that the wording "comprising" used in the description of the present invention refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof. It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical terms and scientific terms) have the same meaning as the general understanding of those skilled in the art in the field to which the present invention belongs. It should also be understood that terms such as those defined in general dictionaries should be understood to have a meaning consistent with the meaning in the context of the prior art, and will not be interpreted in an idealized or overly formal sense unless specifically defined as here.

[0028] Flip-chip ball grid array (FC-BGA) substrates feature ultra-high precision and ultra-high density, and are primarily used in large-scale integrated circuit packaging applications such as CPUs and GPUs. Currently, they are the most advanced IC packaging substrates. However, due to the high number of layers, large area, and high circuit density of FCBGA substrates, their processing is far more difficult than that of general packaging substrates, placing high demands on the primary raw material, build-up films. Thermal expansion of the resin system in existing build-up films can generate thermal stress, which, if excessive, can undermine the reliability of the FC-BGA substrate and its packaging system. Furthermore, build-up films are primarily composed of flammable polymer materials, which release large amounts of smoke and toxic gases during combustion. Therefore, enhancing the flame retardancy of polymer materials has become a key area of ​​focus for build-up films.

[0029] Based on this, the present invention provides a flame-retardant build-up adhesive film for FC-BGA package carrier, which comprises, by weight:

[0030] Wherein, the curing agent includes phosphorus-containing cyanate.

[0031] Specifically, the present invention uses a curing agent in combination with an inorganic filler to form a composite flame retardant system based on components such as epoxy resin, phenoxy resin, and a curing accelerator, thereby ensuring the application of the build-up film in FC-BGA packaging carriers. The curing agent is a phosphorus-containing cyanate. When burned, the phosphorus-based group will generate a phosphaphenanthrene group in the gas phase, which can capture free radicals of the gas-phase cracking gas to form a stable structure and exert a free radical quenching effect. At the same time, the nitrogen-containing structure can also obtain a hindered amine structure with a quenching effect, forming a non-flammable gas, which exerts a gas-phase dilution effect. The two can work together in the gas phase to effectively improve the flame retardant efficiency of the build-up film.

[0032] Preferably, the inorganic filler is selected from one or both of modified boron nitride nanotubes and modified silicon dioxide; the modified boron nitride nanotubes are hydroxylated boron nitride nanotubes; and the modified silicon dioxide is carboxylated silicon dioxide.

[0033] The preparation method of the hydroxylated boron nitride nanotubes comprises the following steps:

[0034] A10. Place 100 mg of boron nitride nanotubes in 50 mL of 3 mol / L HCl solution, heat at 90°C for 10 min, filter, and dry in an oven at 40°C to obtain purified boron nitride nanotubes.

[0035] A20. Disperse 30 mg of the purified boron nitride nanotubes in 10 mL of HNO3 (8 mol / L) solution, ultrasonicate for 1 h, stir at 70°C overnight, centrifuge and wash, place in an oven at 60°C, and bake for 8 h to obtain hydroxylated boron nitride nanotubes.

[0036] The hydroxyl groups of hydroxylated boron nitride nanotubes not only play a catalytic role in promoting the polymerization of cyanate esters, but also can react chemically with cyanate esters. In the early stage of the reaction, the hydroxyl groups act as a catalyst for the triazine cyclization reaction of cyanate esters, and the triazine rings generated by the cyanate reaction reduce the thermal expansion coefficient of the system; in the middle stage of the reaction, the hydroxyl groups are reactants, which can make the hydroxylated boron nitride nanotubes react with phosphorus-containing cyanate esters, and achieve composite flame retardancy through the three elements of phosphorus, nitrogen and boron; at the same time, by mixing hydroxylated boron nitride nanotubes with epoxy resin, the continuous reaction of hydroxyl and epoxy groups can form a highly cross-linked polyether structure, which uses the interconnected structure to limit the movement of polymer chain segments and reduce thermal expansion.

[0037] The preparation method of the carboxylated silica is as follows: 2 g of silane coupling agent KH550 and 2 g of succinic anhydride are weighed, the two are evenly dispersed in 200 ml of N,N-dimethylformamide (DMF), and after stirring for 3 hours, 10 g of silica particles are added thereto, and stirring is continued for 5 hours. Then, the mixture is washed with anhydrous ethanol and deionized water three times, and dried at 80° C. for 10 hours to obtain carboxylated silica.

[0038] Carboxylated silica and hydroxylated boron nitride nanotubes react through carboxyl groups and hydroxyl groups, forming a network structure through inorganic fillers, forming a protective layer on the surface of polymer materials such as epoxy resin, realizing the role of a protective barrier, while isolating heat transfer, and ultimately improving the flame retardant effect of the build-up film; at the same time, the carboxyl group of carboxylated silica can react with the epoxy group in the epoxy resin, thereby increasing the stacking density of the molecular chain and silica. The denser the stacking, the smaller the free volume, and the movement space of the epoxy resin molecular chain segments is restricted, thereby obtaining good thermal expansion performance.

[0039] Preferably, the phenoxy resin is selected from any one or a combination of at least two of FX280 (Nippon Steel Corporation, Japan), FX293 (Nippon Steel Corporation, Japan), YX8100 (Mitsubishi Chemical Corporation), YX7553BH30 (Mitsubishi Chemical Corporation), YX7200B35 (Mitsubishi Chemical Corporation), and TER240C30 (Guangdong Tongyu).

[0040] In some embodiments, the curing agent further comprises one or more of a maleimide curing agent, a phenolic curing agent, an active ester curing agent, a carbodiimide curing agent, a phenol curing agent, a naphthol curing agent, a cyanate curing agent, and a benzoxazine curing agent.

[0041] Preferably, the phosphorus-containing cyanate is selected from one or more of phosphorus-containing cyanate I, phosphorus-containing cyanate II, phosphorus-containing cyanate III and phosphorus-containing cyanate IV; wherein the structural formula of the phosphorus-containing cyanate I is:

[0042] The structural formula of the phosphorus-containing cyanate II is:

[0043] The structural formula of the phosphorus-containing cyanate III is:

[0044] The structural formula of the phosphorus-containing cyanate IV is:

[0045] When phosphorus-containing cyanate burns, the phosphorus-based groups will produce phosphine-phenanthrene groups in the gas phase, which can capture the free radicals of the gas-phase cracking gas, form a stable structure, and play a free radical quenching role; and the nitrogen-containing structure of the cyanate can also obtain a hindered amine structure with quenching effect, forming a non-flammable gas, and playing a gas-phase dilution role. The two can cooperate with each other in the gas phase to enhance the flame retardant effect.

[0046] In some embodiments, the composition further comprises 3 to 9 parts of an auxiliary agent and / or 200 to 300 parts of an organic solvent.

[0047] In some embodiments, the epoxy resin is selected from one or more of bisphenol epoxy resin, biphenyl epoxy resin, naphthalene epoxy resin, naphthol epoxy resin, linear phenolic epoxy resin, dicyclopentadiene epoxy resin, aralkyl phenolic epoxy resin, aralkyl biphenyl phenolic epoxy resin, and naphthol phenolic epoxy resin; the curing accelerator is selected from one or more 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; the auxiliary agent is selected from one or more of a thickener, a defoamer, a leveling agent, a leveling agent, an adhesion-imparting agent, and a colorant; the organic solvent is selected from one or more of toluene, xylene, butanone, methyl ethyl ketone, cyclohexanone, ethyl acetate, and N,N-dimethylformamide.

[0048] The present invention also provides a method for preparing a flame-retardant FC-BGA package carrier build-up adhesive film as described in the above embodiment of the present invention, referring to FIG1 , which comprises the steps of:

[0049] S10, providing epoxy resin, curing agent, phenoxy resin, curing accelerator, and inorganic filler;

[0050] S20, mixing epoxy resin, curing agent, phenoxy resin, curing accelerator, and inorganic filler, coating the mixture on a substrate, and drying the mixture to obtain the flame-retardant FC-BGA package carrier build-up adhesive film.

[0051] Preferably, the thickness of the substrate is 10 to 150 μm (for example, it can be 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm, 120 μm, 130 μm, 140 μm or 150 μm, etc.), and more preferably 25 to 50 μm.

[0052] It should be noted that the present invention does not specifically limit the choice of substrate; any commonly used substrate in the art can be used, including, but not limited to, PET release film, polyethylene film, polypropylene film, or polyvinyl chloride film. To facilitate subsequent removal of the substrate, the polyethylene film, polypropylene film, or polyvinyl chloride film can be corona treated before use.

[0053] Preferably, the drying temperature is 80-130°C, for example, 80°C, 85°C, 90°C, 95°C, 100°C, 105°C, 110°C, 115°C, 120°C, 125°C or 130°C.

[0054] 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.

[0055] The present invention also provides a use of the flame-retardant build-up adhesive film for FC-BGA package carrier described in the above solution of the present invention in the FC-BGA package carrier.

[0056] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them, and are intended only to illustrate the present invention and in no way limit the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort shall fall within the scope of protection of the present invention.

[0057] The sources of some components in the following examples and comparative examples are as follows:

[0058] Epoxy resin: naphthalene-type epoxy resin ("HP4032SS" manufactured by DIC Corporation), naphthalene-type epoxy resin ("EXA-7311-G4" manufactured by DIC Corporation), naphthalene-type epoxy resin ("ESN475V" manufactured by Nippon Steel & Sumitomo Metal Chemicals Co., Ltd.); Curing agent: cyanate curing agent ("BA230S75" manufactured by Lonza Corporation), active ester curing agent ("HPC-8000-65T" manufactured by DIC Corporation); Phenoxy resin: "YL7553BH30" manufactured by Mitsubishi Chemical Corporation of Japan; Silica: CAS No. 7631-86-9; Boron nitride nanotubes: CAS No. 10043-11-5.

[0059] Example 1

[0060] A build-up adhesive film, wherein the raw materials of the build-up adhesive film include, by weight: 3 parts of naphthalene epoxy resin (HP4032SS), 12 parts of naphthalene epoxy resin (EXA-7311-G4), 15 parts of naphthalene epoxy resin (ESN475V), 20 parts of phosphorus cyanate ester I, 5 parts of active ester curing agent (HPC-8000-65T), 3 parts of phenoxy resin (YX7553BH30), 0.1 part of 4-dimethylaminopyridine (DMAP), 80 parts of carboxylated silica, 20 parts of hydroxylated boron nitride nanotubes and 300 parts of cyclohexanone.

[0061] The preparation method of the build-up film is as follows: after uniformly mixing the raw material components according to the above proportions, coating the mixture on a PET release film, drying at 80° C. for 10 minutes, and removing the PET release film to obtain a build-up film with a thickness of 100 μm.

[0062] Example 2

[0063] This embodiment provides a build-up adhesive film. The raw materials of the build-up adhesive film include, by weight: 5 parts of naphthalene epoxy resin (HP4032SS), 15 parts of naphthalene epoxy resin (EXA-7311-G4), 20 parts of naphthalene epoxy resin (ESN475V), 18 parts of phosphorus cyanate II, 2 parts of active ester curing agent (HPC-8000-65T), 1 part of phenoxy resin (YX7553BH30), 0.05 parts of 4-dimethylaminopyridine (DMAP), 70 parts of carboxylated silica, 10 parts of hydroxylated boron nitride nanotubes, and 200 parts of cyclohexanone.

[0064] The preparation method of the build-up film is as follows: after uniformly mixing the raw material components according to the above proportions, coating the mixture on a PET release film, drying at 130° C. for 3 minutes, and removing the PET release film to obtain a build-up film with a thickness of 10 μm.

[0065] Example 3

[0066] This embodiment provides a build-up adhesive film. The raw materials of the build-up adhesive film include, by weight: 5 parts of naphthalene epoxy resin (HP4032SS), 15 parts of naphthalene epoxy resin (EXA-7311-G4), 18 parts of naphthalene epoxy resin (ESN475V), 20 parts of phosphorus cyanate IV, 2 parts of active ester curing agent (HPC-8000-65T), 2 parts of phenoxy resin (YX7553BH30), 0.08 parts of 4-dimethylaminopyridine (DMAP), 75 parts of carboxylated silica, 15 parts of hydroxylated boron nitride nanotubes and 250 parts of cyclohexanone.

[0067] The preparation method of the build-up film is as follows: after uniformly mixing the raw material components according to the above proportions, coating the mixture on a PET release film, drying at 110° C. for 5 minutes, and removing the PET release film to obtain a build-up film with a thickness of 40 μm.

[0068] Comparative Example 1

[0069] This comparative example provides a build-up adhesive film and a preparation method thereof. The only difference from Example 1 is that in this comparative example, 20 parts of phosphorus-containing cyanate ester I are replaced with 20 parts of cyanate curing agent (BA230S75) and the inorganic filler is replaced with 100 parts of silica. The other component conditions and preparation method are the same as those in Example 1.

[0070] Comparative Example 2

[0071] This comparative example provides a build-up adhesive film and a preparation method thereof. The only difference from Example 1 is that the inorganic filler in this comparative example is replaced with 100 parts of silicon dioxide, and the other component conditions and preparation method are the same as those in Example 1.

[0072] Comparative Example 3

[0073] This comparative example provides a build-up adhesive film and a preparation method thereof. The only difference from Example 1 is that in this comparative example, 20 parts of phosphorus-containing cyanate ester I are replaced with 20 parts of cyanate curing agent (BA230S75), and the inorganic filler is replaced with 100 parts of carboxylated silica. The other component conditions and preparation method are the same as those in Example 1.

[0074] Comparative Example 4

[0075] This comparative example provides a build-up adhesive film and a preparation method thereof. The only difference from Example 1 is that in this comparative example, 20 parts of phosphorus-containing cyanate ester I are replaced with 20 parts of cyanate curing agent (BA230S75), and the inorganic filler is replaced with 100 parts of hydroxylated boron nitride nanotubes. The other component conditions and preparation method are the same as those in Example 1.

[0076] The performance of the build-up films provided in the above examples and comparative examples was tested using the following test methods:

[0077] Thermal expansion coefficient: The layered adhesive film with PET release film provided in the above-mentioned embodiments and comparative examples was cured at 100°C for 30 min and at 190°C for 90 min, and then the release film was peeled off to obtain a test sample; the test sample was cut into test pieces with a width of about 3 mm and a length of about 120 mm, and a thermal mechanical analysis was performed using a thermomechanical analysis device ("TMA450" of TA Company, USA) 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 thermal expansion coefficient in the range of 25°C to 150°C.

[0078] Evaluation of warpage height: The build-up films with PET release films provided in the above examples and comparative examples were cut into 300×300 mm samples, pressed onto 35 μm copper foil using a vacuum laminator, and placed horizontally on a flat marble table to observe the maximum warpage value (in mm).

[0079] Flame retardancy: The build-up films with PET release films provided in the above examples and comparative examples were laminated to a substrate (MCL-E-705G, Hitachi Chemical, Japan) using a laminating machine. The build-up films (without the PET release film) were laminated to both sides of the substrate to form a laminate. After lamination, the PET release film was removed from the laminate, and the build-up films were thermally cured (at 190°C for 90 minutes) to form a cured product on both sides of the substrate. The laminate (approximately 380 μm thick) was cut into 12.7 mm x 127 mm samples with a 1.27 mm margin. Testing was performed according to the UL-94V standard, and the test results were recorded.

[0080] The performance test results of the build-up films provided in the examples and comparative examples are shown in Table 1:

[0081] Table 1 Test results

[0082] As can be seen from Table 1, when comparing Comparative Example 1 with Example 1, when the inorganic filler and the curing agent are not improved, the thermal expansion coefficient is high, the warpage height is also large, and the flame retardant performance of the produced build-up film is also relatively poor; when comparing Comparative Example 2 with Example 1, it can be seen that when only the curing agent is improved, although the flame retardant performance is improved compared with the prior art, the thermal expansion coefficient and the warpage height are relatively large, and the optimal performance of the embodiment of the present invention cannot be achieved; when comparing Comparative Example 3 with Example 1, it can be seen that when the curing agent is not improved and only the existing inorganic filler is replaced with carboxylated silica, the flame retardant performance is poor, the thermal expansion coefficient and the warpage height are also relatively large, and the performance of the embodiment of the present invention cannot be achieved; when comparing Comparative Example 4 with Example 1, It can be seen that when the curing agent is not improved and only the existing inorganic filler is replaced with hydroxylated boron nitride nanotubes, it cannot form a film and therefore is not comparable. In summary, the improvement of the curing agent in the build-up adhesive film of the present invention is indispensable, and when the improved curing agent and the improved inorganic filler are used together to form a composite flame retardant system, the flame retardant efficiency of the build-up adhesive film can be improved and the film can achieve optimal performance, thereby facilitating the application of the build-up adhesive film in FC-BGA package carriers.

[0083] In summary, the present invention has the following beneficial effects: (1) When the phosphorus-containing cyanate of the present invention is burned, the phosphorus-based group will generate a phosphine-phenanthrene group in the gas phase, which can capture the free radicals of the gas-phase cracking gas, form a stable structure, and play a free radical quenching role; and the nitrogen-containing structure of the cyanate can also obtain a hindered amine structure with a quenching effect, forming a non-flammable gas, playing a gas-phase dilution role, and the two can cooperate with each other in the gas phase to enhance the flame retardant effect; (2) The hydroxyl group of the boron nitride nanotube of the present invention not only plays a catalytic role in promoting the polymerization of cyanate, but also can react chemically with cyanate, and the triazine ring generated by the cyanate reaction reduces the thermal expansion coefficient of the system; in the middle stage of the reaction, the hydroxyl group is a reactant, which can make the hydroxylated boron nitride nanotube react with the phosphorus-containing cyanate, through phosphorus, The three elements of nitrogen and boron realize composite flame retardancy; at the same time, the continuous reaction of hydroxyl groups and epoxy groups of epoxy resin can form a highly cross-linked polyether structure, which restricts the movement of polymer chain segments with the help of the interconnected structure and reduces thermal expansion; (3) carboxylated silica and hydroxylated boron nitride nanotubes react through carboxyl groups and hydroxyl groups, forming a network structure through inorganic fillers, forming a protective layer on the surface of polymer materials such as epoxy resin, realizing the role of a protective barrier, while isolating heat transfer, and ultimately improving the flame retardant effect of the build-up film; in addition, the carboxyl groups of carboxylated silica can react with the epoxy groups in epoxy resin, thereby increasing the stacking density of the molecular chain and silica. The denser the stacking, the smaller the free volume, and the movement space of the epoxy resin molecular chain segments is limited, thereby obtaining good thermal expansion performance.

[0084] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A flame retardant FC-BGA package substrate build-up film, characterized in that: In parts by weight, it includes: Wherein, the curing agent includes phosphorus-containing cyanate.

2. The flame-retardant FC-BGA package substrate build-up adhesive film according to claim 1, characterized in that: The inorganic filler is selected from one or both of modified boron nitride nanotubes and modified silicon dioxide; the modified boron nitride nanotubes are hydroxylated boron nitride nanotubes; and the modified silicon dioxide is carboxylated silicon dioxide.

3. The flame-retardant FC-BGA package substrate build-up adhesive film according to claim 1, characterized in that: The curing agent further includes one or more of a maleimide curing agent, a phenolic curing agent, an active ester curing agent, a carbodiimide curing agent, a phenol curing agent, a naphthol curing agent, and a benzoxazine curing agent.

4. The flame-retardant FC-BGA package substrate build-up adhesive film according to claim 1, characterized in that: The phosphorus-containing cyanate is selected from one or more of phosphorus-containing cyanate I, phosphorus-containing cyanate II, phosphorus-containing cyanate III and phosphorus-containing cyanate IV; wherein the phosphorus-containing cyanate I has a structural formula of: The structural formula of the phosphorus-containing cyanate II is: The structural formula of the phosphorus-containing cyanate III is: The structural formula of the phosphorus-containing cyanate IV is:

5. The flame-retardant FC-BGA package substrate build-up adhesive film according to claim 1, characterized in that: The epoxy resin is selected from one or more of bisphenol epoxy resin, biphenyl epoxy resin, naphthalene epoxy resin, naphthol epoxy resin, linear phenolic epoxy resin, dicyclopentadiene epoxy resin, aralkyl phenolic epoxy resin, aralkyl biphenyl phenolic epoxy resin, and naphthol phenolic epoxy resin; the curing accelerator is selected from one or more 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.

6. The flame-retardant FC-BGA package substrate build-up adhesive film according to claim 1, characterized in that: The invention also comprises 3 to 9 parts of auxiliary agents and / or 200 to 300 parts of organic solvents.

7. The flame-retardant FC-BGA package substrate build-up adhesive film according to claim 6, characterized in that: The auxiliary agent is selected from one or more of a thickener, a defoamer, a leveling agent, a leveling agent, an adhesion-imparting agent, and a colorant; and the organic solvent is selected from one or more of toluene, xylene, butanone, methyl ethyl ketone, cyclohexanone, ethyl acetate, and N,N-dimethylformamide.

8. A method for preparing a flame-retardant build-up adhesive film for a carrier board of a FC-BGA package according to any one of claims 1 to 7, characterized in that: Includes steps: Provide epoxy resin, curing agent, phenoxy resin, curing accelerator, inorganic filler; The epoxy resin, the curing agent, the phenoxy resin, the curing accelerator and the inorganic filler are mixed, coated on the substrate and dried to obtain the flame-retardant FC-BGA package carrier build-up adhesive film.

9. The method for preparing a flame-retardant build-up adhesive film for a carrier board for FC-BGA packaging according to claim 8, characterized in that: The thickness of the substrate is 10 to 150 μm; the drying temperature is 80 to 130° C., and the drying time is 3 to 10 minutes.

10. Use of the flame-retardant build-up adhesive film for FC-BGA package carrier according to any one of claims 1 to 7 in FC-BGA package carrier.

Images