Dispersion liquid, slurry and use thereof

Abstract

Embodiments of the present application provide a dispersion liquid. The dispersion liquid comprises silicon dioxide modified particles and an organic solvent, and the silicon dioxide modified particles comprise aromatic group-containing alkoxysilane modified silicon dioxide particles. The silicon dioxide modified particles in the dispersion liquid have good dispersity, and the dispersion liquid has high transparency and good stability. The dispersion liquid can be mixed with an epoxy resin to prepare a slurry having high solid content, high dispersity, and low viscosity, and the slurry is used as an underfill material, so as to improve the service reliability of an electronic device. The dispersion liquid can also be mixed with an organic silicon material to prepare a slurry having high solid content, high transparency, and low viscosity, and the slurry is used for preparing an optical product, so that the optical product has excellent optical properties while having good processability and mechanical properties. The embodiments of the present application also provide a slurry comprising the dispersion liquid, and a use of the slurry.

Description

Dispersions, slurries and their applications

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on July 31, 2023, with application number 202310962366.6 and application name “Dispersion, slurry and its application”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The embodiments of the present application relate to the technical field of electronic device preparation, and in particular to a dispersion liquid, a slurry and applications thereof. Background Art

[0003] Nano-silica is widely used in the field of electronic materials and optoelectronic materials, including integrated circuit packaging materials, photovoltaic materials, LED materials, transistor materials, etc. However, existing nano-silica added to epoxy resin, silicone and other systems often has poor dispersibility, resulting in increased viscosity of the system and affecting the transparency of the original system. In addition, the preparation of existing nano-silica may introduce Na + 、Cl -1 These impurity ions will corrode metal circuits and have a serious impact on packaging reliability.

[0004] Summary of the Invention

[0005] In view of this, an embodiment of the present application provides a dispersion in which the silica-modified particles have good dispersibility, high transparency and good stability. The dispersion can be mixed with epoxy resin to prepare a slurry with high solid content, high dispersion and low viscosity, which is used as a bottom filling material to improve the packaging effect.

[0006] Specifically, a first aspect of an embodiment of the present application provides a dispersion comprising modified silica particles and an organic solvent, wherein the modified silica particles comprise alkoxysilane-modified silica particles containing an aromatic group.

[0007] The dispersion provided in the embodiments of the present application is a silica dispersion containing silica particles modified with an alkoxysilane containing an aromatic group. By modifying the silica particles with an alkoxysilane containing an aromatic group, the present application can effectively improve the dispersibility of the silica particles in the dispersion, and improve the stability and transparency of the dispersion. The dispersion can then be mixed with an epoxy resin to prepare a slurry with high solid content, high dispersion, and low viscosity, which is used as a bottom filling material. While achieving low viscosity and thixotropy, it can effectively improve the problem of particle sedimentation, thereby improving the packaging effect and improving the reliability of electronic devices. The dispersion can also be mixed with an organic silicon material to prepare a slurry with high solid content, high transparency, and low viscosity, which is used in the preparation of optical products, so that the optical products have good processability and mechanical properties while obtaining excellent optical properties.

[0008] In an embodiment of the present application, the number of carbon atoms of the aromatic group-containing alkoxysilane is less than or equal to 18.

[0009] In the embodiment of the present application, the molecular weight of the aromatic alkoxysilane is less than or equal to 600. Controlling the molecular weight of the aromatic alkoxysilane to a smaller value can better control the size of the surface modification groups of the modified silica particles and also help avoid steric hindrance affecting the modification effect.

[0010] In the embodiments of the present application, the weight percentage of the modified groups derived from the aromatic alkoxysilane in the modified silica particles is 20% to 45%. Controlling the amount of modified groups on the modified silica particles within a suitable range can further enhance the dispersibility of the silica particles in the dispersion, improving the stability and transparency of the dispersion.

[0011] In the embodiment of the present application, the organic solvent includes one or more of N,N-dimethylformamide (DMF), ketone solvents, ester solvents, and benzene solvents. The organic solvent can be selected according to the application needs and system requirements. Among them, the ester solvent can include ethyl acetate, and the benzene solvent can include toluene.

[0012] In the embodiment of the present application, the dispersion does not contain water. The dispersion of the present application does not contain water, which is beneficial to improving the dispersibility of the modified silica particles.

[0013] In an embodiment of the present application, the dispersion does not contain metal ions. In an embodiment of the present application, the dispersion does not contain halogens. The presence of impurity metal ions and halogens in the underfill material can corrode the metal circuits of the chip, seriously affecting chip reliability. The silica dispersion of the present application does not contain metal ions and halogens. Using it as a filler in the preparation of the underfill material can effectively prevent the impact of metal ion impurities and halogen impurities on packaging reliability.

[0014] In the embodiment of the present application, the particle size D50 of the modified silica particles is 10 nm to 100 nm. A suitable particle size of the modified silica particles is conducive to their uniform dispersion in the dispersion liquid, and is also conducive to better achieving complete filling when used as an underfill material, thereby improving packaging reliability.

[0015] In the embodiment of the present application, the particle size D10 of the modified silica particles is 16 nm to 35 nm, D50 is 20 nm to 50 nm, and D90 is 35 nm to 60 nm. The silica particles are relatively uniform in size and have a narrow particle size distribution, which is beneficial to improving the uniformity of the dispersion.

[0016] In the embodiment of the present application, the particle size distribution coefficient P of the modified silica particles in the dispersion is in the range of 0.07-0.17, where P = (D90-D10) / D50. A particle size distribution coefficient of the modified silica particles within this range can better improve the dispersibility of the dispersion.

[0017] In the embodiment of the present application, the dispersion is a monodisperse system. A monodisperse system generally refers to a dispersion system with a single dispersed phase and a narrow particle size distribution, and the particle size distribution is normal or approximately normal.

[0018] In embodiments of the present application, the dispersion has a visible light transmittance of 80% to 99% when the solids content is 35% to 50%. The silica dispersion of the present embodiment, by modifying the silica particles with an aromatic alkoxysilane, can effectively improve the dispersibility of the silica particles in the dispersion and enhance the transparency of the dispersion, making it suitable for applications requiring high transparency.

[0019] In an embodiment of the present application, the dispersion is prepared by synthesizing silica particles in alcohol and water using an alkoxysilane as a silicon source and ammonia as a catalyst, followed by solvent replacement using the organic solvent, and modification of the silica particles using an alkoxysilane containing an aromatic group. The dispersion of the present application is prepared using the above process, which reduces the amount of solvent used, provides mild reaction conditions, and achieves uniform dispersion without the introduction of a dispersant or co-dispersant. Furthermore, the process does not introduce metal ions or halogens, resulting in a high-purity dispersion. The dispersion is applicable to a variety of systems.

[0020] A second aspect of the present invention provides a method for preparing a dispersion, comprising the following steps:

[0021] Alkoxysilane is used as a silicon source and ammonia water is used as a catalyst to react in alcohol and water to obtain a silica particle dispersion;

[0022] The silica particle dispersion is first subjected to a solvent replacement treatment using an organic solvent, and then the silica particles are modified using an alkoxysilane containing an aromatic group to obtain a dispersion; or

[0023] The silica particles in the silica particle dispersion are first modified with an aromatic alkoxysilane, and then a solvent replacement treatment is performed with an organic solvent to obtain a dispersion; the dispersion comprises modified silica particles and the organic solvent, and the modified silica particles comprise silica particles modified with an aromatic alkoxysilane.

[0024] The preparation method of the dispersion provided in the embodiments of the present application adopts a liquid phase method and introduces solvent replacement to prepare a dispersion containing modified silica particles, which can significantly reduce the amount of solvent used. In addition, the reaction conditions of the entire preparation process are mild, and a uniform dispersion effect can be achieved without the introduction of a dispersant or a dispersant aid. In addition, the preparation process does not introduce metal ions or halogens, and the dispersion has high purity. The dispersion has good dispersibility and high transparency, and can be applied to a variety of systems to meet different application requirements.

[0025] A third aspect of the present invention provides applications of the dispersion described in the first aspect or the dispersion prepared by the preparation method described in the second aspect in electronic product manufacturing, optical products, coating materials, functional film materials, adhesives, fillers, medical products, building materials, nanomaterial manufacturing, and environmental engineering. The dispersions in the present invention have good dispersibility of the silica particles and high stability and transparency. These dispersions can be used as base materials in a variety of systems to meet different application requirements.

[0026] The fourth aspect of the embodiment of the present application provides a slurry, which includes epoxy resin and the silica-modified particles in the dispersion described in the first aspect of the embodiment of the present application or the silica-modified particles in the dispersion prepared by the preparation method described in the second aspect.

[0027] The slurry provided in the embodiments of this application is an epoxy resin system slurry. It is prepared by mixing the dispersion of the first embodiment of this application with an epoxy resin and removing the organic solvent. The residual organic solvent content in the resulting slurry is less than 1%. The resulting slurry has high solids content, high dispersion, and low viscosity. When used as an underfill material, it can achieve low viscosity and low thixotropy while effectively improving particle settling, enhancing packaging effectiveness, and improving the reliability of electronic devices.

[0028] In the embodiments of the present application, the room temperature viscosity of the slurry is less than 30 Pa·s, and the viscosity at 110°C is less than 0.075 Pa·s. The low viscosity of the slurry at both room temperature and 110°C helps ensure good fluidity and filling properties during packaging and filling, thereby better meeting various chip filling requirements, including electronic device potting, board-level CUF, and chip-level CUF, thereby improving packaging effects.

[0029] In the embodiment of the present application, the visible light transmittance of the slurry is 40%-50%. The epoxy resin used in the epoxy resin system slurry itself does not have high transparency and has a certain haze. The high visible light transmittance of the epoxy resin system slurry finally indicates that the particle distribution in the system is relatively uniform.

[0030] In the embodiment of the present application, the epoxy resin accounts for 50% to 65% by weight in the slurry. The appropriate epoxy resin content can enable the slurry to meet the basic physical properties of the package, achieve filling, and better ensure a strong bond between the chip, solder bumps, and substrate.

[0031] In the embodiment of the present application, the silica-modified particles comprise 30% to 50% by weight of the slurry. By controlling the silica-modified particle content to a higher level, the slurry achieves lower viscosity, better dispersibility, and stability, enabling the slurry to be used as an underfill material, better meeting narrow gap filling requirements, while also improving particle sedimentation and enhancing packaging reliability.

[0032] The fifth aspect of the embodiments of the present application provides a slurry, which includes an organic silicon material and the silica-modified particles in the dispersion described in the first aspect of the embodiments of the present application or the silica-modified particles in the dispersion prepared by the preparation method described in the second aspect.

[0033] The slurry provided in the embodiment of the present application is a silicone system slurry, which is prepared by mixing the dispersion of the first aspect of the embodiment of the present application with an silicone material and removing the organic solvent. The residual amount of organic solvent in the obtained slurry is less than 1%. The obtained slurry has the characteristics of high solid content, high transparency and low viscosity, and can be used for the preparation of optical products, so that the optical products can obtain excellent optical properties while obtaining good processability and mechanical properties.

[0034] In the embodiment of the present application, when the solid content of the slurry is 35%-50%, the visible light transmittance is 80%-97%.

[0035] In the embodiment of the present application, the room temperature viscosity of the slurry is not higher than 5 Pa·s. The slurry has a low viscosity at room temperature and can obtain good fluidity, which is conducive to molding into optical products of various shapes and sizes, thereby improving product quality.

[0036] A sixth aspect of the present invention provides a method for preparing a slurry, comprising the following steps:

[0037] Alkoxysilane is used as a silicon source and ammonia water is used as a catalyst to react in alcohol and water to obtain a silica particle dispersion;

[0038] The silica particle dispersion is first subjected to a solvent replacement treatment using an organic solvent, and then the silica particles are modified using an alkoxysilane containing an aromatic group to obtain a dispersion; or

[0039] First, the silica particles in the silica particle dispersion are modified with an alkoxysilane containing an aromatic group, and then a solvent replacement treatment is performed with an organic solvent to obtain a dispersion; the dispersion comprises modified silica particles and the organic solvent, and the modified silica particles comprise silica particles modified with the alkoxysilane containing an aromatic group;

[0040] The dispersion is mixed with epoxy resin or silicone material to obtain slurry.

[0041] The slurry preparation method provided in the embodiments of the present application adopts a liquid phase method and introduces solvent replacement to prepare a dispersion containing modified silica particles, which can significantly reduce the amount of solvent used. In addition, the reaction conditions of the entire preparation process are mild, and a uniform dispersion effect can be achieved without the introduction of a dispersant or a dispersant aid. In addition, the preparation process does not introduce metal ions or halogens, and the dispersion has high purity. The dispersion has good dispersibility and high transparency, and can be directly mixed with epoxy resin, silicone materials, etc. to prepare a slurry that meets different application requirements.

[0042] The seventh aspect of the present application provides the use of the slurry described in the fourth aspect of the present application in electronic packaging, as well as in coating materials, functional film materials, adhesives, and fillers. The epoxy resin system slurry provided in the present application has the characteristics of good dispersibility, excellent stability, and low viscosity. When used in the above-mentioned fields, it can effectively improve the quality of the resulting products and enhance the service reliability of the products.

[0043] In embodiments of the present application, the application of the slurry in electronic packaging includes the use of the slurry as an underfill material for chip packaging. For example, it can be electronic device potting, board-level CUF (capillary underfill), or chip-level CUF. In some embodiments, the slurry is filled between the substrate and the electronic components and, after heating and curing, forms a solid filling layer. This can reduce stress impact caused by the difference in thermal expansion coefficient between the electronic components and the substrate, improve the strength and connection reliability of the packaging structure, and enhance the overall drop resistance of the packaging structure.

[0044] In an eighth aspect, the present invention provides a packaged device comprising the cured product of the slurry described in the fourth aspect. The packaged device of the present invention comprises the cured product of the epoxy resin system slurry, which is beneficial for improving the reliability of the packaged device.

[0045] In an embodiment of the present application, the packaging device includes a substrate and an electronic component disposed on the substrate. A plurality of solder bumps are provided on a surface of the electronic component facing the substrate. An underfill layer is provided between the solder bumps, and the underfill layer includes the solidified material. In an embodiment of the present application, the packaging device further includes a plastic package covering the surface of the electronic component. In the present application, the electronic component includes but is not limited to a chip. When the electronic component is a chip, the packaging device is a chip packaging structure.

[0046] The present invention also provides a terminal device, comprising a circuit board and a packaging device according to the eighth aspect of the present invention, disposed on the circuit board. The terminal device according to the present invention can improve service reliability by using the packaging device provided in the present invention.

[0047] The present invention also provides a communication device, comprising the packaging device according to the eighth aspect of the present invention. The terminal device according to the present invention adopts the packaging device provided in the present invention to improve the service reliability of the communication device.

[0048] The present invention also provides a communication base station, comprising the packaging device according to the eighth aspect of the present invention. The communication base station according to the present invention can improve the service reliability of the communication base station by using the packaging device provided in the present invention.

[0049] The present application also provides applications of the slurry described in the fifth aspect of the present application in optical products, coating materials, medical products, electronic product manufacturing, and building materials. The silicone-based slurry provided in the present application has the advantages of good dispersibility, excellent stability, low viscosity, and high transparency. Application in the aforementioned fields can effectively improve the performance of the resulting products. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] FIG1 is a schematic structural diagram of a packaging device 100 provided in one embodiment of the present application;

[0051] FIG2 is a schematic diagram of a packaged device 100 disposed on a circuit board according to an embodiment of the present application;

[0052] FIG3 is a schematic structural diagram of a terminal device 200 provided in an embodiment of the present application;

[0053] FIG4 is a SEM (Scanning Electron Microscope) image of modified silica particles in the dispersion prepared in Example 1 of the present application;

[0054] FIG5 is a graph showing the particle size distribution of modified silica particles in the dispersion prepared in Example 1 of the present application;

[0055] FIG6 is a physical photograph of the epoxy resin nano-silica slurry prepared in Example 1 of the present application;

[0056] FIG7 is a SEM image of the epoxy resin nano-silica slurry prepared in Example 1 of the present application;

[0057] FIG8 is a SEM image of a chip after dispensing with the epoxy resin nano-silica slurry prepared in Example 1 of the present application;

[0058] FIG9 is a physical photograph of the silicone oil nano-silica slurry prepared in Example 3 of the present application;

[0059] FIG10 is a photograph of the DMF nano-silica dispersion prepared in Example 4 of the present application. DETAILED DESCRIPTION

[0060] The embodiments of the present application will be described below with reference to the accompanying drawings.

[0061] The packaging material is filled between the substrate and the chip and is thermally cured to form a firm bottom filling glue layer, which can reduce the stress impact caused by the difference in thermal expansion coefficient between the chip and the substrate, protect the chip, substrate and welding bumps, improve the strength and connection reliability of the packaging structure, and enhance the overall anti-drop performance of the packaging structure. In order to increase the number of I / O and shorten the signal transmission distance in the current advanced packaging structure, the packaging gap is getting smaller and smaller, and the packaging interface is becoming more complex. Therefore, the packaging material is required to have good fluidity and low viscosity to better match the increasingly narrow and increasingly complex packaging requirements in the field of electronic packaging. At the same time, it can better avoid the problem of uneven performance of the bottom filling glue layer due to particle sedimentation, which affects the packaging reliability. Based on this, the embodiment of the present application provides a dispersion liquid, and a slurry prepared using the dispersion liquid.

[0062] An embodiment of the present application provides a dispersion liquid, which is a silica dispersion liquid. The dispersion liquid includes modified silica particles and an organic solvent. The modified silica particles include alkoxysilane-modified silica particles containing an aromatic group.

[0063] The dispersion provided in the embodiments of the present application contains silica particles modified with an alkoxysilane containing an aromatic group. By modifying the silica particles with an alkoxysilane containing an aromatic group, the present application can effectively improve the dispersibility of the silica particles in the dispersion, and improve the stability and transparency of the dispersion. The dispersion can then be mixed with an epoxy resin to prepare a slurry with high solid content, high dispersion, and low viscosity, which is used as a bottom filling material. While achieving low viscosity and thixotropy, it can effectively improve the problem of particle sedimentation, thereby improving the packaging effect and improving the reliability of electronic devices. The dispersion can also be mixed with an organic silicon material to prepare a slurry with high solid content, high transparency, and low viscosity, which is used in the preparation of optical products, so that the optical products have good processability and mechanical properties while obtaining excellent optical properties.

[0064] In an embodiment of the present application, the number of carbon atoms in the aromatic group-containing alkoxysilane is less than or equal to 18. In some embodiments, the number of carbon atoms in the aromatic group-containing alkoxysilane may be 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, or 18. A smaller number of carbon atoms can make the structure of the modifying group simpler, the raw materials of the modifier are more readily available, and it is easier to modify the silica particles.

[0065] In an embodiment of the present application, the molecular weight of the aromatic-containing alkoxysilane is less than or equal to 600. In some embodiments, the molecular weight of the aromatic-containing alkoxysilane is 100, 150, 180, 200, 250, 300, 400, 500, or 600. Controlling the molecular weight of the aromatic-containing alkoxysilane to a smaller value can better control the size of the surface modification groups of the modified silica particles and also help avoid steric hindrance affecting the modification effect.

[0066] In some embodiments of the present application, the alkoxysilane containing an aromatic group can be one or more of methoxysilane containing an aromatic group, ethoxysilane containing an aromatic group, propoxysilane containing an aromatic group, and butoxysilane containing an aromatic group. The aromatic group can be a substituted or unsubstituted phenyl, a substituted or unsubstituted naphthyl, etc. In some embodiments, the alkoxysilane containing an aromatic group is one or more of phenyltrimethoxysilane, phenyltris(dimethylsiloxane)silane, phenyltriethoxysilane, and phenyltris(trimethylsiloxane)silane. The alkoxysilane containing an aromatic group can be chemically bonded to the surface of the silica particles to reduce the amount of active hydroxyl groups on the surface of the silica particles, while effectively improving the hydrophobicity of the silica particles, thereby improving the dispersibility and stability of the silica dispersion.

[0067] In embodiments of the present application, the weight percentage of modifying groups derived from aromatic alkoxysilanes in the modified silica particles is 20%-45%. In some embodiments, the weight percentage of modifying groups derived from aromatic alkoxysilanes in the modified silica particles is 20%, 25%, 30%, 35%, 40%, or 45%. Controlling the amount of modifying groups on the modified silica particles within a suitable range can improve the dispersibility of the silica particles in the dispersion, while also better preventing gelation and enhancing the stability and transparency of the dispersion.

[0068] In the embodiment of the present application, the organic solvent includes one or more of N,N-dimethylformamide, ketone solvents, ester solvents, and benzene solvents. Among them, the ester solvents can include, for example, methyl formate, ethyl formate, propyl formate, isopropyl formate, butyl formate, isobutyl formate, pentyl formate, isoamyl formate, benzyl formate, hexyl formate, trimethyl orthoformate [trimethoxymethane], methyl acetate, ethyl acetate, vinyl acetate, propyl acetate, isopropyl acetate, allyl acetate [allyl acetate], butyl acetate, isobutyl acetate, sec-butyl acetate, tert-butyl acetate, pentyl acetate, isoamyl acetate, hexyl acetate, etc. Ketone solvents can include, for example, methyl formate, ethyl formate, propyl formate, isopropyl acetate, sec-butyl acetate, tert-butyl acetate, pentyl acetate, isoamyl acetate, hexyl acetate, etc. For example, it can be acetone, methyl acetone, butanone, 2-pentanone, 3-pentanone, acetylacetone [2,4-pentanedione], 3-methyl-2-butanone, 2-hexanone, 3-hexanone, 2-methyl-3-pentanone, 3,3-dimethyl-2-butanone [pinacolone], 4-methyl-2-pentanone, 2-heptanone, 3-heptanone, 4-heptanone, 2,4-dimethyl-3-pentanone, 2-octanone, 5-methyl-3-heptanone, 2,6-dimethyl-4-heptanone, etc., and the benzene solvent can be, for example, toluene. The organic solvent can be selected according to the needs of the application and the system requirements. For example, if the dispersion is subsequently mixed with an epoxy resin to prepare a slurry, the organic solvent can be a good solvent for the epoxy resin, such as ethyl acetate.

[0069] In the embodiment of the present application, the dispersion does not contain water. The dispersion of the present application does not contain water, which is beneficial to improving the dispersibility of the modified silica particles and can effectively avoid the introduction of water affecting the reliability verification of subsequent devices.

[0070] In embodiments of the present application, the dispersion does not contain metal ions. In embodiments of the present application, the dispersion does not contain halogens. The presence of impure metal ions and halogens in underfill materials can corrode the metal circuits of the chip, seriously impacting chip reliability. The silica dispersion of the present application does not contain metal ions and halogens. Using it as a filler in the preparation of underfill materials can effectively prevent the impact of metal ion and halogen impurities on packaging reliability.

[0071] In an embodiment of the present application, the particle size D50 of the silica-modified particles is 10 nm to 100 nm. For example, the particle size D50 of the silica-modified particles is 10 nm, 15 nm, 18 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 85 nm, 90 nm, 95 nm, or 100 nm. A suitable particle size of the silica-modified particles facilitates uniform dispersion in the dispersion and facilitates complete filling when used as an underfill material, effectively preventing sedimentation and improving packaging reliability.

[0072] In some embodiments of the present application, the particle size D10 of the silica-modified particles is 16nm-35nm, D50 is 20nm-50nm, and D90 is 35nm-60nm. In some embodiments, the particle size D10 of the silica-modified particles is 16nm, 18nm, 20nm, 25nm, 30nm, or 35nm. In some embodiments, the particle size D50 of the silica-modified particles is 20nm, 25nm, 30nm, 35nm, 40nm, 45nm, or 50nm. In some embodiments, the particle size D90 of the silica-modified particles is 35nm, 40nm, 45nm, 50nm, 55nm, or 60nm. The particle size of silica is relatively uniform and the particle size distribution is narrow, which is conducive to improving the uniformity of the dispersion.

[0073] The particle sizes D10, D50, and D90 of the modified silica particles can be obtained by analysis using a dynamic light scattering particle size analyzer (DLS).

[0074] In embodiments of the present application, the particle size distribution coefficient P of the modified silica particles in the dispersion is in the range of 0.07-0.17, where P = (D90-D10) / D50. In some embodiments, the particle size distribution coefficient P of the modified silica particles in the dispersion is 0.07, 0.08, 0.10, 0.12, 0.14, 0.15, 0.16, or 0.17. A particle size distribution coefficient of the modified silica particles within this range can better improve the dispersibility of the dispersion.

[0075] In the embodiments of the present application, the dispersion is a monodisperse system. A monodisperse system refers to a dispersion system with a single dispersed phase and a narrow particle size distribution, and the particle size distribution is normal or approximately normal.

[0076] In the embodiment of the present application, when the solid content of the dispersion is 35%-50%, the visible light transmittance is 80%-99%. Among them, the solid content can be, but not limited to, 35%, 40%, 45%, and 50%, and the visible light transmittance can be, but not limited to, 80%, 85%, 90%, 95%, 98%, and 99%. The solid content is calculated as the proportion of the total mass of the modified silica particles in the dispersion relative to the total mass of the dispersion. The visible light transmittance of the dispersion can be measured by a spectrophotometer. The silica dispersion of the embodiment of the present application, by modifying the silica particles with an alkoxysilane containing an aromatic group, can effectively improve the dispersibility of the silica particles in the dispersion, improve the transparency of the dispersion, and make it conducive to application scenarios with high requirements for transparency.

[0077] In an embodiment of the present application, the dispersion is prepared by synthesizing silica particles in alcohol and water using an alkoxysilane as a silicon source and ammonia as a catalyst, followed by solvent replacement with the organic solvent and modification of the silica particles with an aromatic alkoxysilane. The dispersion prepared by the above process can reduce the amount of solvent used, maintain mild reaction conditions, and achieve uniform dispersion without the need for dispersants or co-dispersants. Furthermore, the process does not introduce metal ions or halogens, resulting in a high-purity dispersion. The dispersion is applicable to a variety of systems.

[0078] An embodiment of the present application provides a method for preparing a dispersion, comprising the following steps:

[0079] Step (1): using alkoxysilane as a silicon source and ammonia as a catalyst, reacting in alcohol and water to obtain a silica particle dispersion;

[0080] The alkoxysilane may be, for example, tetraethoxysilane, i.e., tetraethyl orthosilicate (TEOS), or may be methyl orthosilicate, methyltrimethoxysilane, methyltriethoxysilane, or polysiloxane. The alcohol may be methanol, ethanol, isopropanol, or n-butanol. The reaction temperature during the reaction may be controlled within the range of 60°C to 70°C, e.g., 60°C, 65°C, or 70°C, and the reaction time may be 4 to 8 hours, e.g., 4 hours, 6 hours, or 8 hours. Stirring may be performed during the reaction, with the stirring speed controlled within the range of 200 rpm to 600 rpm.

[0081] Wherein, relative to the amount of alcohol, the amount of water used can be 1 mol / L-6 mol / L, the amount of ammonia water used can be 0.1 mol / L-3 mol / L, and the amount of alkoxysilane used can be 0.05 mol / L-3 mol / L. In some embodiments, the amount of water used can be 1 mol / L, 2 mol / L, 3 mol / L, 4 mol / L, 5 mol / L, or 6 mol / L. In some embodiments, the amount of ammonia water used can be 0.1 mol / L, 0.3 mol / L, 0.5 mol / L, 0.7 mol / L, 0.9 mol / L, 1 mol / L, 1.5 mol / L, 2 mol / L, 2.5 mol / L, or 3 mol / L. In some embodiments, the amount of alkoxysilane used can be 0.05 mol / L, 0.1 mol / L, 0.2 mol / L, 0.3 mol / L, 0.5 mol / L, 0.7 mol / L, 0.9 mol / L, 1 mol / L, 1.5 mol / L, 2 mol / L, 2.5 mol / L, or 3 mol / L.

[0082] Before performing the solvent replacement treatment in step (2), the method further includes concentrating the silica particle dispersion obtained in step (1) at a first temperature, which may be in the range of 40°C to 50°C.

[0083] Step (2): The silica particle dispersion is first subjected to a solvent replacement treatment using an organic solvent, and then the silica particles are modified using an alkoxysilane containing an aromatic group to obtain a dispersion; the obtained dispersion includes silica-modified particles and an organic solvent, and the silica-modified particles include silica particles modified with an alkoxysilane containing an aromatic group.

[0084] The organic solvent can be selected based on actual needs and can be one or more of N,N-dimethylformamide, ketone solvents, ester solvents, and benzene solvents, as described above. For example, if the dispersion is subsequently mixed with an epoxy resin to prepare a slurry, the organic solvent can be a good solvent for the epoxy resin, such as ethyl acetate.

[0085] After the solvent exchange treatment is completed, a concentration treatment can be performed before modifying the silica particles with an aromatic alkoxysilane. The concentration treatment temperature can be within the range of 40°C to 50°C. When modifying the silica particles with an aromatic alkoxysilane, the pH of the system after the solvent exchange and concentration treatments is adjusted to 9-10 with aqueous ammonia.

[0086] Another embodiment of the present application provides a method for preparing a dispersion, comprising the following steps:

[0087] Step (1): using alkoxysilane as a silicon source and ammonia as a catalyst, reacting in alcohol and water to obtain a silica particle dispersion;

[0088] The alkoxysilane may be, for example, tetraethoxysilane, i.e., tetraethyl orthosilicate (TEOS), or may be methyl orthosilicate, methyltrimethoxysilane, methyltriethoxysilane, or polysiloxane. The alcohol may be methanol, ethanol, isopropanol, or n-butanol. The reaction temperature during the reaction may be controlled within the range of 60°C to 70°C, e.g., 60°C, 65°C, or 70°C, and the reaction time may be 4 to 8 hours, e.g., 4 hours, 6 hours, or 8 hours. Stirring may be performed during the reaction, with the stirring speed controlled within the range of 200 rpm to 600 rpm.

[0089] Wherein, relative to the amount of alcohol, the amount of water used can be 1 mol / L-6 mol / L, the amount of ammonia water used can be 0.1 mol / L-3 mol / L, and the amount of alkoxysilane used can be 0.05 mol / L-3 mol / L. In some embodiments, the amount of water used can be 1 mol / L, 2 mol / L, 3 mol / L, 4 mol / L, 5 mol / L, or 6 mol / L. In some embodiments, the amount of ammonia water used can be 0.1 mol / L, 0.3 mol / L, 0.5 mol / L, 0.7 mol / L, 0.9 mol / L, 1 mol / L, 1.5 mol / L, 2 mol / L, 2.5 mol / L, or 3 mol / L. In some embodiments, the amount of alkoxysilane used can be 0.05 mol / L, 0.1 mol / L, 0.2 mol / L, 0.3 mol / L, 0.5 mol / L, 0.7 mol / L, 0.9 mol / L, 1 mol / L, 1.5 mol / L, 2 mol / L, 2.5 mol / L, or 3 mol / L.

[0090] Step (2): first modifying the silica particles in the silica particle dispersion with an aromatic alkoxysilane, and then performing solvent replacement treatment with an organic solvent to obtain a dispersion; the obtained dispersion includes silica-modified particles and an organic solvent, and the silica-modified particles include silica particles modified with an aromatic alkoxysilane.

[0091] The organic solvent can be selected based on actual needs and can be one or more of N,N-dimethylformamide, ketone solvents, ester solvents, and benzene solvents, as described above. For example, if the dispersion is subsequently mixed with an epoxy resin to prepare a slurry, the organic solvent can be a good solvent for the epoxy resin, such as ethyl acetate.

[0092] After the modification is completed, a concentration treatment may be performed first, followed by a solvent replacement treatment. The temperature of the concentration treatment may be in the range of 40° C. to 50° C. The concentration treatment is a reduced pressure concentration treatment performed under vacuum conditions.

[0093] The preparation method of the dispersion provided in the embodiments of the present application adopts a liquid phase method and introduces solvent replacement to prepare a dispersion containing modified silica particles, which can significantly reduce the amount of solvent used. In addition, the reaction conditions of the entire preparation process are mild, and a uniform dispersion effect can be achieved without the introduction of a dispersant or a dispersant aid. In addition, the preparation process does not introduce metal ions or halogens, and the dispersion has high purity. The dispersion has good dispersibility and high transparency, and can be applied to a variety of systems to meet different application requirements.

[0094] The dispersions provided in the examples of the present application or the dispersions prepared by the above-described preparation methods can be used in the fields of electronic product manufacturing, optical products, coating materials, functional film materials, adhesives, fillers, medical products, building materials, nanomaterial manufacturing, environmental protection engineering, etc. The dispersions in the examples of the present application have good dispersibility of the silica particles, and the dispersions have high stability and transparency. They can be used as basic raw materials and are applicable to a variety of systems to meet different application requirements.

[0095] An embodiment of the present application provides a slurry, which includes epoxy resin and the silica-modified particles in the dispersion described in the embodiment of the present application.

[0096] The slurry provided in the examples of this application is an epoxy resin-based slurry. It is prepared by mixing the dispersion described in the examples with an epoxy resin and removing the organic solvent. The residual organic solvent content in the resulting slurry is less than 1%. The resulting slurry exhibits high solids content, high dispersion, and low viscosity. When used as an underfill material, it achieves low viscosity and low thixotropy while effectively reducing particle settling, enhancing packaging performance and improving the reliability of electronic devices.

[0097] In the embodiments of the present application, the room temperature viscosity of the slurry is less than 30 Pa·s, and the viscosity at 110°C is less than 0.075 Pa·s. The low viscosity of the slurry at both room temperature and 110°C helps ensure good fluidity and filling properties during packaging and filling, thereby better meeting various chip filling requirements, including electronic device potting, board-level CUF, and chip-level CUF, thereby improving packaging effects.

[0098] The slurry of the embodiment of the present application can be stored at room temperature for easy storage.

[0099] In the embodiment of the present application, the visible light transmittance of the slurry is 40%-50%. The epoxy resin used in the epoxy resin system slurry itself does not have high transparency and has a certain haze. The high visible light transmittance of the epoxy resin system slurry finally indicates that the particle distribution in the system is relatively uniform.

[0100] In the embodiment of the present application, the epoxy resin can be one or more of glycidyl ether epoxy resin, glycidyl ester epoxy resin, glycidyl amine epoxy resin, aliphatic epoxy resin, bisphenol F epoxy resin, naphthalene epoxy resin, aminophenol epoxy resin, binaphthyl epoxy resin, bisphenol A epoxy resin, and novolac epoxy resin. In the resin composition, the epoxy resin can be one or a combination of two or more. In some embodiments of the present application, the epoxy resin includes one or more of bisphenol F epoxy resin, aminophenol epoxy resin, bisphenol A epoxy resin, naphthalene epoxy resin, and binaphthyl epoxy resin.

[0101] In the embodiments of the present application, the epoxy resin content in the slurry is 50%-65% by weight. In some embodiments, the epoxy resin content is 50%, 52%, 55%, 60%, 62%, or 65% by weight. The appropriate epoxy resin content ensures that the slurry meets the basic physical properties of the package, achieves filling, and better ensures a strong bond between the chip, solder bumps, and substrate.

[0102] In the embodiments of the present application, the mass proportion of silica-modified particles in the slurry is 30%-50%. In some embodiments, the mass proportion of silica-modified particles in the slurry is 30%, 35%, 40%, 45%, or 50%. By controlling the content of silica-modified particles to a higher level, the slurry can be made to have a lower viscosity, better dispersibility and stability, thereby enabling the slurry to be used as an underfill material, better meeting the needs of narrow gap filling, while also better improving the problem of particle sedimentation and improving packaging reliability.

[0103] In some embodiments of the present application, other resin materials other than epoxy resin may be added to the slurry as needed, and other inorganic fillers other than silica may be added as needed.

[0104] In the embodiment of the present application, an epoxy resin system slurry prepared by using silica modified with an aromatic group using alkoxysilane is used in bottom filling. The thermal expansion coefficient, glass transition temperature, and mechanical properties such as TMA (thermomechanical analysis) and DMA (dynamic thermomechanical analysis) of the entire system can meet the physical property requirements.

[0105] In an embodiment of the present application, when used for bottom filling materials, the slurry is added to the bottom filling glue system, and the bottom filling glue system may include a curing agent. The curing agent may include an amine curing agent and / or an acid anhydride curing agent. In an embodiment of the present application, the acid anhydride curing agent may be one or more of hexahydrophthalic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, hexahydrophthalic anhydride, alkylhexahydrophthalic anhydride, tetrahydrophthalic anhydride, succinic anhydride, methylnadic anhydride, hydrogenated methylnadic anhydride, 5-norbornene-2,3-dianhydride, trialkyltetrahydrophthalic anhydride, etc. In an embodiment of the present application, the amine curing agent may be an aromatic amine curing agent or an aliphatic amine curing agent, wherein the amine curing agent may be, for example, diethyltoluenediamine, polyetheramine, isophoronediamine, 3,3'-dimethyl-4,4'-diamino-dicyclohexylmethane, etc. The underfill system may further include additives, including one or more of a coupling agent, a stress modifier, a curing accelerator, a colorant, a dispersant, an ion trap, a leveling agent, a flame retardant, a release agent, and a flow improver. It is understood that additives may be added according to specific needs.

[0106] The present application also provides examples of the aforementioned slurry for use in electronic packaging, as well as in coating materials, functional film materials, adhesives, and fillers. The slurry in this example exhibits excellent dispersibility, stability, and low viscosity. Application in these areas can effectively improve the quality of the resulting products and enhance their service reliability.

[0107] In embodiments of the present application, the slurry may be used in electronic packaging as an underfill material for chip packaging. Examples include electronic device potting, board-level CUF, and chip-level CUF. In some embodiments, the slurry is filled between the substrate and electronic components and, after heating and curing, forms a solid filling layer. This reduces stress caused by differences in thermal expansion coefficients between the electronic components and the substrate, improves the strength and connection reliability of the package structure, and enhances the overall drop resistance of the package structure.

[0108] In the embodiment of the present application, the electronic components may be chips, transistors (such as diodes, triodes), LEDs, RC-sensing elements (such as resistors, capacitors, inductors), etc. The structural form of the package may be advanced packaging structures such as flip chip, fan-in wafer-level package FOWLP, fan-out wafer-level package FOWLP, through silicon via technology TSV, 2.5D package, 3D package, embedded wafer-level ball grid array package eWLB, etc. It may also be packaging structures such as large-area molding, thin-type grinding-free package, passive device package and POP (package-on-package, package stacking technology) package. The epoxy resin system slurry provided in the embodiment of the present application is a liquid packaging material, which has good packaging filling ability and can better meet the packaging requirements of advanced packaging structures.

[0109] Referring to FIG. 1 , another embodiment of the present application further provides a packaged device 100. FIG. 1 is a schematic structural diagram of packaged device 100 according to one embodiment of the present application. Packaged device 100 may be an electronic device package, and packaged device 100 includes a cured product of the epoxy resin system slurry described in the embodiment of the present application. Packaged device 100 in the embodiment of the present application includes a cured product of the epoxy resin system slurry described above, which helps improve the reliability of the packaged device.

[0110] In some embodiments of the present application, the packaging device 100 includes a substrate 10, an electronic component 20 disposed on the substrate 10, a plurality of solder bumps 30 are provided on the surface of the electronic component 20 facing the substrate 10, and an underfill layer 40 is provided between the solder bumps 30, that is, between the substrate 10, the electronic component 20, and the solder bumps 30. The underfill layer 40 includes a cured product of the epoxy resin system slurry described above in the embodiment of the present application. In an embodiment of the present application, the packaging device 100 also includes a plastic package 60 covering the surface of the electronic component 20. In an embodiment of the present application, the solder bumps 30 are electrically connected to the electronic component 20 through a conductive structure 50 in the substrate 10. Among them, the electronic component 20 can be various components that need to be packaged, including but not limited to one or more of chips, transistors (such as diodes, triodes), LEDs, resistors, capacitors, and inductors (such as resistors, capacitors, inductors), etc. When the electronic component 20 is a chip, the packaging device 100 is a chip packaging structure. The electronic components 20 can be attached to the surface of the substrate 10 by soldering. The substrate 10 can be a redistribution layer (RDL). Referring to Figure 2 , the packaged device 100 can be soldered to the circuit board 101. A plurality of metal balls 70 can be disposed on the side of the substrate 10 away from the electronic components 20. The electronic components 20 in the packaged device 100 can be electrically connected to the circuit board 101 via the conductive structure 50 and the metal balls 70. A filler layer 80 is disposed between the substrate 10, the circuit board 101, and the metal balls 70. This filler layer 80 can also be a cured product comprising the epoxy resin system slurry described in the embodiments of the present application.

[0111] The packaged device 100 of the embodiment of the present application uses the epoxy resin system slurry provided in the embodiment of the present application to encapsulate electronic components, which has good filling properties, high process operability, and high packaging reliability.

[0112] Referring to FIG3 , an embodiment of the present application further provides a terminal device 200, which includes a housing 201 and a circuit board and a packaging device 100 disposed within the housing 201. Inside the terminal device 200, the packaging device 100 may be disposed on the circuit board 101 as shown in FIG2 and electrically connected to the circuit board 101. The terminal device 200 may be a mobile phone, tablet computer, laptop computer, portable computer, smart wearable product, television, video recorder, camcorder, radio, tape recorder, vehicle-mounted terminal, mouse, keyboard, microphone, scanner, or other product. The use of the packaging device provided by the embodiment of the present application in the terminal device of the embodiment of the present application can improve the service reliability of the terminal device.

[0113] The present application also provides a communication device, comprising the packaged device 100 described above in the present application. The packaged device 100 may be electrically connected and fixed to a circuit board. The communication device may be any type of wired or wireless communication device, including but not limited to communication conversion equipment, lightning arresters, antennas, gateways, remote controls, radars, intercoms, switches, routers, and the like. The use of the packaged device provided in the present application in the terminal device of the present application can improve the service reliability of the communication device.

[0114] The present invention also provides a communication base station, comprising the packaged device 100 described above. Packaged device 100 may be electrically connected and fixed to a circuit board. The communication base station of the present invention employs the packaged device provided in the present invention to improve the service reliability of the communication base station.

[0115] Another embodiment of the present application provides a slurry, which includes an organosilicon material and the silica-modified particles in the dispersion liquid described in the embodiment of the present application, and is an organosilicon system slurry.

[0116] The silicon bond in the organosilicon system is very weak, which leads to its generally poor mechanical properties. In order to enhance the mechanical strength and stiffness of the organosilicon system so that it can meet the application requirements of scenarios such as high-performance coatings, adhesives and composite materials, it is usually necessary to add some inorganic fillers such as silica for reinforcement. However, in certain application scenarios, such as automotive glass, optical materials and other optical products, it is hoped that the transparency of the system will not be affected while reinforcement is performed. The slurry provided in the embodiment of the present application is an organosilicon system slurry, which is obtained by mixing the above-mentioned dispersion of the embodiment of the present application with an organosilicon material and removing the organic solvent. The residual amount of organic solvent in the obtained slurry is less than 1%. The obtained slurry has the characteristics of high solid content, high transparency and low viscosity, and can be used for the preparation of optical products, so that the optical products can obtain excellent optical properties while obtaining good processability and mechanical properties.

[0117] In the embodiment of the present application, the organosilicon material is a liquid organosilicon material, and the organosilicon material can be a silicone oil-based organosilicon material. The silicone oil-based organosilicon material can be ordinary silicone oil, i.e., methyl silicone oil, or it can be a modified silicone oil. In some embodiments, the modified silicone oil can be one or more of epoxy-modified silicone oil, polyether-modified silicone oil, and amino-modified silicone oil. Epoxy-modified silicone oil is a type of silicone oil containing epoxy groups in the side chains or end groups of polydimethylsiloxane. Polyether-modified silicone oil is a polydimethylsiloxane containing polyether groups in the side chains or end groups, and the polyether groups are, for example, polyoxyethylene, polyoxypropylene, and fatty alcohol polyoxyethylene polyoxypropylene ether groups. Amino-modified silicone oil is a polydimethylsiloxane containing amino groups in the side chains or end groups.

[0118] In the embodiment of the present application, when the solid content of the slurry is 35%-50%, the visible light transmittance is 80%-97%. Among them, the solid content can be, but is not limited to, 35%, 40%, 45%, and 50%, and the visible light transmittance can be, but is not limited to, 80%, 85%, 90%, 95%, and 97%. The solid content is calculated as the ratio of the total mass of the modified silica particles in the slurry to the total mass of the slurry. The visible light transmittance of the slurry can be measured by a spectrophotometer. The organosilicon system slurry of the embodiment of the present application has excellent transparency due to the use of a dispersion of silica particles modified with alkoxysilane containing an aromatic group and mixed with an organosilicon material, which is beneficial for the application of the slurry in application scenarios with high requirements for transparency.

[0119] In the embodiment of the present application, the room temperature viscosity of the slurry is not higher than 5 Pa·s, i.e., less than or equal to 5 Pa·s. The slurry has a low viscosity at room temperature and can obtain good fluidity, which is conducive to molding into optical products of various shapes and sizes, thereby improving product quality.

[0120] The present application also provides examples of the use of the aforementioned organosilicon slurry in optical products, coating materials, medical products, electronic product manufacturing, and building materials. The organosilicon slurry provided in the present application examples has the characteristics of good dispersibility, excellent stability, low viscosity, and high transparency. Its application in the aforementioned fields can effectively improve the performance of the resulting products.

[0121] The present invention also provides a method for preparing a slurry, comprising the following steps:

[0122] Step (1): using alkoxysilane as a silicon source and ammonia as a catalyst, reacting in alcohol and water to obtain a silica particle dispersion;

[0123] Step (2): first subjecting the silica particle dispersion to a solvent replacement treatment using an organic solvent, and then modifying the silica particles using an alkoxysilane containing an aromatic group to obtain a dispersion; or

[0124] First, the silica particles in the silica particle dispersion are modified with an alkoxysilane containing an aromatic group, and then a solvent replacement treatment is performed with an organic solvent to obtain a dispersion; the obtained dispersion comprises modified silica particles and the organic solvent, and the modified silica particles comprise silica particles modified with the alkoxysilane containing an aromatic group;

[0125] Step (3): mixing the dispersion with epoxy resin or silicone material to obtain a slurry.

[0126] Among them, step (1) and step (2) are methods for preparing a dispersion, which are consistent with the above and will not be repeated here. It can be understood that considering that step (3) mixes the dispersion with the epoxy resin or the organosilicon material, the organic solvent used in step (2) for solvent replacement is a good solvent for the epoxy resin or the organosilicon material. A good solvent refers to a solvent with high solubility that can dissolve the epoxy resin or the organosilicon material well. In some embodiments, the boiling point of the organic solvent is lower than 120°C. The organic solvent has a lower boiling point, which is beneficial to temperature control of the preparation process.

[0127] In step (3), after the dispersion is mixed with the epoxy resin or organosilicon material, a concentration process is further included. The concentration process temperature is greater than 55° C., for example, 60° C. The concentration process is performed under reduced pressure under vacuum conditions. The organic solvent can be removed during the concentration process.

[0128] The slurry preparation method provided in the embodiment of the present application adopts a liquid phase method and introduces solvent replacement to prepare a dispersion containing modified silica particles, which can significantly reduce the amount of solvent used. The reaction conditions of the entire preparation process are mild, and a uniform dispersion effect can be achieved without introducing a dispersant or a dispersant aid. In addition, the preparation process does not introduce metal ions or halogens, and the dispersion has high purity. The dispersion has good dispersibility and high transparency, and can be directly mixed with epoxy resin to prepare a high-solid content, high-dispersion, low-viscosity slurry for bottom filling materials. While achieving low viscosity and thixotropy, it can effectively improve the problem of particle sedimentation, thereby improving the packaging effect and improving the reliability of electronic devices. It can also be directly mixed with silicone materials to prepare a slurry with high solid content, high transparency, and low viscosity, which is used in the preparation of optical products, so that the optical products have good processability and mechanical properties while obtaining excellent optical properties.

[0129] The embodiments of the present application are further described below with reference to a number of embodiments.

[0130] The ionic solid content of the slurry was measured by TGA (Thermo Gravimetric Analyzer, thermal gravimetric analysis), and the test conditions of TGA were heating from 0°C to 800°C at 20°C / min.

[0131] The viscosity of the slurry was measured using a rheometer at room temperature and 110°C with a shear rate range of 0-100 1 / s, with the corresponding viscosity value at 50 1 / s being taken.

[0132] The visible light transmittance of the slurry or dispersion is measured using an ultraviolet-visible spectrophotometer at room temperature in the visible light range of 300-800 nm.

[0133] Example 1

[0134] The preparation method of the epoxy resin system slurry comprises the following steps:

[0135] (1) Particle formation and solvent replacement:

[0136] Add appropriate amounts of deionized water and ammonia water to 1.2 L of ethanol, and mix and stir at 65°C. After the temperature stabilizes, add TEOS, control the stirring speed to 400 rpm, and react for 6 hours to generate silica particles with a D50 particle size of 30±5 nm. After the reaction is completed, the silica reaction liquid is placed at 40°C and concentrated to 400 mL. Then, 400 mL of ethyl acetate is added and stirred evenly, and then concentrated to 300 mL at 40°C to obtain a silica concentrate.

[0137] (2) Modification:

[0138] Aqueous ammonia was added to the silica concentrate to adjust the pH of the system to 9, 0.5 mL of deionized water was added and stirred evenly, and then 4.8 g of phenyltrimethoxysilane was added and reacted for 6 h to obtain a modified silica sol; then, coarse particles were removed by centrifugation, the centrifugal force was controlled at 424 × g, and the centrifugation was performed for 2 min, and the upper liquid was retained to obtain a dispersion.

[0139] (3) Add epoxy resin:

[0140] 24 g of epoxy resin dissolved in ethyl acetate was added to the dispersion and stirred for 20 minutes. The ethyl acetate was then concentrated at 60°C and removed to obtain a translucent epoxy resin nanosilica slurry with a particle solids content of 36.45%. The resulting epoxy resin nanosilica slurry had a room temperature viscosity of less than 30 Pa·s and a high-temperature viscosity of less than 0.075 Pa·s at 110°C. The measurement gap was 0.2 mm. The fluidity test results of the resulting epoxy resin nanosilica slurry were as follows:

[0141] Figure 4 is an SEM image of the modified silica particles in the dispersion prepared in Example 1 of the present application. As can be seen from Figure 4, in the dispersion prepared in Example 1 of the present application, the particle size of the modified silica particles is uniform and small, at the nanometer level. Figure 5 is a particle size distribution diagram of the modified silica particles in the dispersion prepared in Example 1 of the present application. As can be seen from Figure 5, in the dispersion prepared in Example 1 of the present application, the particle size of the modified silica particles is uniform and narrowly distributed. The figure shows a curve obtained by three parallel measurements, and the peak of the curve is around 30 nm.

[0142] Figure 6 is a photograph of the epoxy resin nano-silica slurry prepared in Example 1 of the present application. As shown in Figure 6, the epoxy resin nano-silica slurry prepared in Example 1 of the present application is a translucent liquid phase system with good fluidity. Figure 7 is a SEM image of the epoxy resin nano-silica slurry prepared in Example 1 of the present application. As shown in Figure 7, the modified silica particles in the epoxy resin nano-silica slurry are well dispersed and there is no agglomeration.

[0143] The epoxy resin nano-silica slurry prepared in Example 1 was prepared as an underfill adhesive and subjected to chip dispensing testing. Figure 8 is a SEM image of a chip section after dispensing using the chip in Example 1 of the present application. The results in Figure 8 show that the epoxy resin nano-silica slurry of the present application does not cause filler phase separation during encapsulation, demonstrating good anti-settling effectiveness.

[0144] Example 2

[0145] The preparation method of the epoxy resin system slurry comprises the following steps:

[0146] (1) Particle generation and modification:

[0147] Add appropriate amounts of deionized water and ammonia water to 1.2 L of ethanol and stir at 65°C. After the temperature stabilizes, add TEOS, control the stirring speed to 400 rpm, and react for 6 hours to produce silica particles with a D50 particle size of 30±5 nm. Add 5.8 g of phenyltrimethoxysilane to the silica reaction solution and react for 6 hours to obtain a modified silica sol.

[0148] (2) Solvent replacement:

[0149] The modified silica sol was concentrated to 400 mL at 40°C, and then 400 mL of ethyl acetate was added and stirred evenly for solvent replacement at 40°C. After the temperature stabilized, the solution was concentrated to about 300 mL, and then centrifuged at 424×g for 2 minutes, and the upper dispersion was retained.

[0150] (3) Add epoxy resin:

[0151] 24 g of epoxy resin dissolved in ethyl acetate was added to the dispersion. After stirring for 20 minutes, the mixture was concentrated at 60°C and the ethyl acetate was removed to obtain a translucent epoxy resin nanosilica slurry with a particle solids content of 38.56%. The resulting epoxy resin nanosilica slurry had a room temperature viscosity of less than 30 Pa·s and a high-temperature viscosity of less than 0.075 Pa·s at 110°C.

[0152] Example 3

[0153] The preparation method of the organosilicon system slurry comprises the following steps:

[0154] (1) and (2) are the same as in Example 1 or Example 2;

[0155] (3) Add silicone oil:

[0156] 20 g of silicone oil dissolved in ethyl acetate was added to the dispersion. After stirring for 20 minutes, the mixture was concentrated at 60°C and the ethyl acetate was removed by evaporation to obtain a highly transparent silicone oil nano-silica slurry. The resulting silicone oil nano-silica slurry was measured by oxygen TGA (Thermo Gravimetric Analyzer) to have a solid content of 44.58%. The viscosity of the resulting silicone oil nano-silica slurry at room temperature was less than 5 Pa·s, and the measurement gap was 0.05 mm.

[0157] Table 1 shows the transmittance data of pure organic silicone oil and silicone oil nano-silica slurry in the visible light wavelength range of 300nm-800nm, all measured three times and the average value is taken. Figure 9 is a physical photo of the silicone oil nano-silica slurry prepared in Example 3 of the present application.

[0158] Table 1 Transmittance results of pure silicone oil and silicone oil nano-silica slurry

[0159] As can be seen from the results in Table 1, the transmittance of the silicone oil nano-silica slurry in the embodiment of the present application is 94.6% of the transmittance of pure silicone oil. That is, after the modified silica dispersion in the embodiment of the present application is mixed with silicone oil, even at a high solid content, the visible light transmittance of the system will not be significantly reduced, and the silicone oil nano-silica slurry can maintain a high transparency.

[0160] As shown in FIG9 , the silicone oil nano-silica slurry is a highly transparent liquid phase system with good transparency.

[0161] Example 4

[0162] The preparation method of DMF nano-silicon dioxide dispersion comprises the following steps:

[0163] (1) Particle generation and modification:

[0164] 2.8 mol / L (relative to ethanol) of deionized water and 0.6 mol / L (relative to ethanol) of aqueous ammonia were added to 1.2 L of ethanol and stirred at 65°C. After the temperature stabilized, 0.224 mol / L (relative to ethanol) of TEOS was added, the stirring speed was controlled at 400 rpm, and the reaction was carried out for 6 hours to generate silica particles with a D50 particle size of 30±5 nm. 5.8 g of phenyltrimethoxysilane was added to the silica reaction solution, and the mixture was reacted for 6 hours to obtain a modified silica sol.

[0165] (2) Solvent replacement:

[0166] The modified silica sol was concentrated to 400 mL at 40°C, and then 400 mL of DMF was added and stirred evenly. The solution was concentrated and replaced at 80°C. After the temperature stabilized, the solvent was concentrated to a solution volume of about 300 mL. The solution was then centrifuged at a controlled centrifugal force of 424×g for 2 minutes to remove coarse particles, thereby obtaining a uniform and transparent DMF silica dispersion.

[0167] Table 2 shows the transmittance data of pure DMF solvent and DMF nano-silica dispersion in the visible light wavelength range of 300nm-800nm, all of which were measured three times and the average value was taken. Figure 10 is a physical photo of the DMF nano-silica dispersion prepared in Example 4 of the present application.

[0168] Table 2 Transmittance results of pure DMF solvent and DMF nano-silica dispersion

[0169] From the results in Table 2, it can be seen that the transmittance of the DMF nano-silica dispersion of the embodiment of the present application is 99.2% of the transmittance of pure DMF, that is, the modified silica dispersion of the embodiment of the present application does not significantly reduce the visible light transmittance of the system compared with a simple organic solvent.

[0170] As shown in FIG10 , the DMF nano-silica dispersion of the embodiment of the present application has good transparency.

[0171] It should be understood that the first, second and various numerical numbers involved in this document are only distinguished for the convenience of description and are not intended to limit the scope of this application.

[0172] In this application, "and / or" describes the relationship between related objects, indicating that three possible relationships exist. For example, "A and / or B" can mean: A exists alone, A and B exist simultaneously, and B exists alone. A and B can be singular or plural. The character " / " generally indicates that the related objects are in an "or" relationship.

[0173] In this application, "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can all mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0174] In this application, “-” represents a range value, including the endpoint values ​​at both ends. For example, the value of a can be 0.5-15, which means that the value of a can be between 0.5 and 15, and includes the endpoint values ​​0.5 and 15.

[0175] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. Some or all of the steps can be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

Claims

1. A dispersion, characterized in that: The dispersion includes silica-modified particles and an organic solvent, and the silica-modified particles include silica particles modified with alkoxysilane containing an aromatic group.

2. The dispersion according to claim 1, characterized in that The aromatic group-containing alkoxysilane has 18 or less carbon atoms.

3. The dispersion according to claim 1 or 2, characterized in that The molecular weight of the aromatic group-containing alkoxysilane is less than or equal to 600.

4. The dispersion according to any one of claims 1 to 3, characterized in that In the modified silica particles, the weight proportion of the modified groups derived from the aromatic group-containing alkoxysilane is 20%-45%.

5. The dispersion according to any one of claims 1 to 4, characterized in that The organic solvent includes one or more of N,N-dimethylformamide, ketone solvents, ester solvents, and benzene solvents.

6. The dispersion according to any one of claims 1 to 5, characterized in that The dispersion does not contain water.

7. The dispersion according to any one of claims 1 to 6, characterized in that The dispersion does not contain metal ions; or the dispersion does not contain halogens.

8. The dispersion according to any one of claims 1 to 7, characterized in that The particle size D50 of the modified silica particles is 10nm-100nm.

9. The dispersion according to claim 8, characterized in that The particle size D10 of the modified silicon dioxide particles is 16nm-35nm, D50 is 20nm-50nm, and D90 is 35nm-60nm.

10. The dispersion according to claim 9, characterized in that In the dispersion, the particle size distribution coefficient P of the modified silica particles is in the range of 0.07-0.17, wherein P=(D90-D10) / D50.

11. The dispersion according to any one of claims 1 to 10, characterized in that When the solid content of the dispersion is 35%-50%, the visible light transmittance is 80%-99%.

12. The dispersion according to any one of claims 1 to 11, characterized in that The dispersion liquid is obtained by synthesizing silicon dioxide particles in alcohol and water using alkoxysilane as a silicon source and ammonia water as a catalyst, then using the organic solvent for solvent replacement, and using alkoxysilane containing an aromatic group to modify the silicon dioxide particles.

13. A method for preparing a dispersion, comprising the following steps: Alkoxysilane is used as a silicon source and ammonia water is used as a catalyst to obtain a silica particle dispersion by reaction in alcohol and water; The silica particle dispersion is first subjected to solvent replacement treatment with an organic solvent, and then the silica particles are modified with an alkoxysilane containing an aromatic group to obtain a dispersion; or the silica particles in the silica particle dispersion are first modified with an alkoxysilane containing an aromatic group, and then solvent replacement treatment is performed with an organic solvent to obtain a dispersion; the dispersion includes modified silica particles and the organic solvent, and the modified silica particles include silica particles modified with an alkoxysilane containing an aromatic group.

14. Use of the dispersion according to any one of claims 1 to 12 or the dispersion prepared by the preparation method according to claim 13 in the manufacture of electronic products, optical products, coating materials, functional film materials, adhesives, fillers, medical products, building materials, nanomaterials, and environmental protection projects.

15. A slurry, characterized in that: The slurry comprises epoxy resin, and the silicon dioxide modified particles in the dispersion according to any one of claims 1 to 12 or the silicon dioxide modified particles in the dispersion obtained by the preparation method according to claim 13.

16. The slurry according to claim 15, characterized in that The room temperature viscosity of the slurry is lower than 30 Pa·s, and the viscosity at 110° C. is lower than 0.075 Pa·s.

17. The slurry according to claim 15 or 16, characterized in that The visible light transmittance of the slurry is 40%-50%.

18. The slurry according to any one of claims 15 to 17, characterized in that In the slurry, the epoxy resin accounts for 50%-65% by mass; the silicon dioxide modified particles account for 30%-50% by mass.

19. A slurry, characterized in that: The slurry comprises an organic silicon material and the silicon dioxide modified particles in the dispersion according to any one of claims 1 to 12 or the silicon dioxide modified particles in the dispersion obtained by the preparation method according to claim 13.

20. The slurry according to claim 19, characterized in that When the solid content of the slurry is 35%-50%, the visible light transmittance is 80%-97%.

21. The slurry according to claim 19 or 20, characterized in that The room temperature viscosity of the slurry is not higher than 5 Pa·s.

22. A method for preparing a slurry, comprising the following steps: Alkoxysilane is used as a silicon source and ammonia water is used as a catalyst to obtain a silica particle dispersion by reaction in alcohol and water; The silica particle dispersion is first subjected to solvent replacement treatment with an organic solvent, and then the silica particles are modified with an alkoxysilane containing an aromatic group to obtain a dispersion; or the silica particles in the silica particle dispersion are first modified with an alkoxysilane containing an aromatic group, and then the dispersion is subjected to solvent replacement treatment with an organic solvent to obtain a dispersion; the dispersion comprises modified silica particles and the organic solvent, and the modified silica particles comprise silica particles modified with an alkoxysilane containing an aromatic group; The dispersion is mixed with epoxy resin or silicone material to obtain slurry.

23. Use of the slurry according to any one of claims 15 to 18 in electronic packaging, and in coating materials, functional film materials, adhesives and fillers.

24. The use according to claim 23, characterized in that The application of the slurry in electronic packaging includes using the slurry as a bottom filling material for chip packaging.

25. A packaged device, characterized in that: The packaging device comprises a cured product of the slurry according to any one of claims 15 to 18.

26. The packaged device according to claim 25, characterized in that The packaging device comprises a substrate and electronic components arranged on the substrate. A surface of the electronic components facing the substrate is provided with a plurality of solder bumps. A bottom filling adhesive layer is provided between the solder bumps. The bottom filling adhesive layer comprises the solidified material.

27. A terminal device, characterized in that: The terminal device includes a circuit board and a packaging device as claimed in claim 25 or 26 arranged on the circuit board.

28. A communication device, characterized in that: The communication device comprises the packaged device according to claim 25 or 26.

29. A communication base station, characterized in that: The communication base station comprises the packaged device as claimed in claim 25 or 26.

30. Use of the slurry according to any one of claims 19 to 21 in optical products, coating materials, medical products, electronic product manufacturing, and building materials.

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