Silver-containing composite slurry and preparation method thereof, and electronic interconnection material

Abstract

The invention discloses a silver-containing composite slurry, a preparation method thereof and an electronic interconnection material. The silver-containing composite slurry comprises, by weight, 60 to 95 parts of metallic silver, 1 to 10 parts of auxiliary agents and 1 to 15 parts of organic microspheres; the metallic silver comprises micron silver particles and nano silver particles, and the organic microspheres are composed of at least one of organic silica gel, polyamide resin, polyester, polyphenylene ether, polyparaphenylene terephthalamide, polyimide resin, polyphenylene sulfide resin and polybutylene terephthalate. The auxiliary agent in the silver-containing composite slurry not only avoids the drastic shrinkage of metallic silver during sintering by adding a certain volume of organic microspheres, but also has a smaller modulus than silver, which reduces the modulus of the composite material as a whole after sintering, thereby reducing the stress caused by the mismatch of thermal expansion coefficients, and can improve the stress problem caused by the inconsistency of thermal expansion coefficients between the electronic interconnection material containing the silver-containing composite slurry and the substrate.

Description

Technical Field

[0001] The invention relates to the field of electronic interconnection materials, and in particular to a silver-containing composite slurry and a preparation method thereof, as well as an electronic packaging interconnection material. Background Art

[0002] Electronic interconnection solder joints are key parts of electronic devices that play multiple roles, such as signal transmission, heat dissipation channels, mechanical support, and environmental protection. They have a very important impact on the performance of the entire electronic circuit and device equipment. In addition to polymer materials such as bonding wires, solders, thermal conductive adhesives, and conductive adhesives, the development direction of electronic interconnection materials is promising low-temperature connection materials. Low-temperature sintered silver is widely studied as a low-temperature connection material because of its good performance.

[0003] In order to improve the sintering performance of silver paste and reduce the sintering temperature of silver paste, the content of nano silver powder in traditional silver paste is very high, or even only contains nano silver powder. Nano silver powder has a very high surface energy, and may shrink violently during the sintering process. There is a huge internal stress, which is easy to produce cracks inside and on the surface of the sintered joint, which will greatly reduce the thermal conductivity, electrical properties and mechanical properties of the sintered joint. Not only that, after the nano silver paste is sintered at high temperature, in the process of cooling to room temperature, due to the inconsistent thermal expansion coefficients between the substrates bonded by the sintered silver, the substrates shrink inconsistently, which will also produce large stress, which is easy to cause stratification between the silver layer and the substrate. Summary of the invention

[0004] Based on this, in order to reduce the overall modulus of the silver-containing composite paste and avoid the problem of excessive stress caused by inconsistent thermal expansion coefficients between substrates, it is necessary to provide a silver-containing composite paste and a preparation method thereof, as well as an electronic packaging interconnection material.

[0005] The present invention provides a silver-containing composite slurry, wherein the raw materials include, by weight: 60 to 95 parts of metallic silver, 1 to 10 parts of an auxiliary agent, and 1 to 15 parts of organic microspheres;

[0006] The metallic silver comprises micron silver particles and nano silver particles in a mass ratio of 0.5:5 to 5:1, the particle size of the nano silver particles is 5 nm to 900 nm, and the particle size of the micron silver particles is 1 μm to 20 μm.

[0007] The organic microspheres are composed of at least one of organic silica gel, polyamide resin, polyester, polyphenylene ether, polyparaphenylene terephthalamide, polyimide resin, polyphenylene sulfide resin and polybutylene terephthalate.

[0008] In one embodiment, the auxiliary agent includes an organic solvent, a thickener and a dispersant in a weight ratio of (2-3):(0.1-0.6):(0.2-0.8):.

[0009] In one embodiment, the organic solvent is selected from at least one of ethanol, ethylene glycol, propylene glycol, glycerol, butanol, polyethylene glycol, butyl carbitol, toluene, xylene, phenol, tributyl phosphate, amyl acetate, tetraethylene glycol butyl ether, triethylene glycol butyl ether and terpineol.

[0010] In one embodiment, the thickener is selected from at least one of polyethylene glycol, hydroxyethyl cellulose, ethyl cellulose and polyvinyl alcohol.

[0011] In one embodiment, the dispersant is selected from at least one of ethyl acetate, sodium lauryl sulfate, polyvinylamide, polyacrylamide, fish oil and soybean lecithin.

[0012] In one embodiment, the organic microspheres have at least one of the following characteristics:

[0013] (1) The particle size of the organic microspheres is 0.5 μm to 20 μm;

[0014] (2) The pyrolysis temperature of the organic microspheres is 300°C to 500°C;

[0015] (3) The Young's modulus of the organic microspheres is 0.2 GPa to 10 GPa.

[0016] Furthermore, the present invention also provides a method for preparing a silver-containing composite slurry, comprising the following steps:

[0017] Prepare the raw materials of the silver-containing composite paste according to the above;

[0018] Mixing the metallic silver, the auxiliary agent and the organic microspheres to prepare a premix;

[0019] The premix is ​​placed in a vacuum of 10 -3 Pa to 10 3 Pa, and stirring is performed until the viscosity of the premix is ​​10 Pa·s to 100 Pa·s.

[0020] In one embodiment, mixing the metallic silver, the additive and the organic microspheres to prepare a premix comprises:

[0021] Mixing the metallic silver, the organic microspheres and the organic solvent, stirring, and preparing a liquid mixture;

[0022] The liquid mixture, the thickener, the dispersant and the defoamer are mixed and dispersed uniformly.

[0023] The present invention further provides an electronic interconnection material, comprising the above silver-containing composite slurry after calcination.

[0024] In one embodiment, during the calcination process, the calcination temperature is 150°C to 250°C.

[0025] The silver-containing composite slurry contains organic microspheres, additives, and metallic silver composed of micron silver particles and nano silver particles. Since the organic microspheres occupy a certain space in the composite material, the shrinkage degree of the silver paste during the sintering process can be reduced, and the shrinkage stress in the sintered body can be improved. In addition, by adding organic microspheres, since the modulus of the organic microspheres is smaller than that of silver, the modulus of the composite material as a whole after sintering can be reduced, and the stress is smaller under the same strain. Therefore, the stress problem caused by the inconsistent thermal expansion coefficient between the electronic interconnect material containing the silver-containing composite slurry and the substrate can be improved. DETAILED DESCRIPTION

[0026] The present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thoroughly understood. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and / or letters in different examples. This repetition is for the purpose of simplicity and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed.

[0027] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the invention, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined. In the description of the present invention, the meaning of "several" is at least one, such as one, two, etc., unless otherwise clearly and specifically defined.

[0028] Unless otherwise indicated, all percentages, fractions and ratios are calculated based on the total mass of the composition of the present invention. Unless otherwise indicated, all masses of listed ingredients are given as active substances, so they do not include solvents or by-products that may be contained in commercially available materials. The term "mass percentage content" herein may be represented by the symbol "%".

[0029] As used herein, "includes," "comprising," "including," "containing," "having," or other variations are intended to encompass non-closed inclusions, and no distinction is made between these terms. The term "comprising" means that other steps and ingredients that do not affect the end result may be added. The term "comprising" also includes the terms "consisting of" and "consisting essentially of." The compositions and methods / processes of the present invention comprise, consist of, and consist essentially of the essential elements and limitations described herein, as well as any additional or optional ingredients, components, steps, or limitations described herein. As used herein, no distinction is made between the terms "efficacy," "performance," "effect," and "efficacy."

[0030] The words "preferably", "more preferably", etc. in the present invention refer to embodiments of the present invention that may provide certain beneficial effects in certain circumstances. However, other embodiments may also be preferred under the same circumstances or other circumstances. In addition, the description of one or more preferred embodiments does not imply that other embodiments are not applicable, nor is it intended to exclude other embodiments from the scope of the present invention.

[0031] When a numerical range is disclosed herein, the above range is considered to be continuous and includes the minimum and maximum values ​​of the range, as well as every value between such minimum and maximum values. Further, when a range refers to an integer, every integer between the minimum and maximum values ​​of the range is included. In addition, when multiple ranges are provided to describe features or characteristics, the ranges can be combined. In other words, unless otherwise indicated, all ranges disclosed herein should be understood to include any and all subranges included therein.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0033] The present invention provides a silver-containing composite slurry, wherein the raw materials include, by mass percentage: 60 to 95 parts of metallic silver, 1 to 10 parts of an auxiliary agent, and 1 to 15 parts of organic microspheres;

[0034] The metallic silver comprises micron silver particles and nano silver particles in a mass ratio of 0.5:5 to 5:1, the particle size of the nano silver particles is 5mn to 900nm, and the particle size of the micron silver particles is 1μm to 20μm.

[0035] The organic microspheres are composed of at least one of organic silica gel, polyamide resin, polyester, polyphenylene ether, polyparaphenylene terephthalamide, polyimide resin, polyphenylene sulfide resin and polybutylene terephthalate.

[0036] Preferably, the particle size of the micron silver particles is 3 μm to 10 μm. Specifically, the particle size of the micron silver particles may be, but is not limited to, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm or 10 μm.

[0037] Furthermore, the particle size of the nanosilver particles is 10nm to 100nm. Specifically, the particle size of the nanosilver particles can be but is not limited to 10nm, 20nm, 30nm, 40nm, 50nm, 60nm, 70nm, 80nm, 90nm or 100nm.

[0038] In a specific example, the auxiliary agent includes an organic solvent, a thickener, and a dispersant in a weight ratio of (2-3):(0.1-0.6):(0.2-0.8).

[0039] In a specific example, the organic solvent is selected from at least one of ethanol, ethylene glycol, propylene glycol, glycerol, butanol, polyethylene glycol, butyl carbitol, toluene, xylene, phenol, tributyl phosphate, amyl acetate, tetraethylene glycol butyl ether, triethylene glycol butyl ether and pinene alcohol.

[0040] In a specific example, the thickener is selected from at least one of polyethylene glycol, hydroxyethyl cellulose, ethyl cellulose and polyvinyl alcohol.

[0041] In a specific example, the dispersant is selected from at least one of ethyl acetate, sodium lauryl sulfate, polyvinylamide, polyacrylamide, fish oil and soybean lecithin.

[0042] In a specific example, the particle size of the organic microspheres is 0.5 μm to 20 μm.

[0043] Preferably, the particle size of the organic microspheres is 3 μm to 10 μm. It is understandable that the particle size of the organic microspheres is but not limited to 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm or 10 μm.

[0044] In a specific example, the content of organic microspheres is 1 to 15 parts. It is understandable that if the content of organic microspheres is too low, it will not relieve stress, and if the content is too high, it will have a significant impact on the thermal conductivity and electrical conductivity of the silver-containing composite slurry after sintering, reducing product performance.

[0045] In a specific example, the pyrolysis temperature of the organic microspheres is 300° C. to 500° C. In order to ensure that the organic microspheres do not overheat and decompose during high-temperature use of the sintered body, which would affect product performance, the pyrolysis temperature should meet the above conditions.

[0046] In a specific example, the Young's modulus of the organic microspheres is 0.2 GPa to 10 GPa, ensuring that the organic microspheres can effectively reduce the modulus of the sintered body.

[0047] Moreover, the addition of the organic microspheres can further hinder cracks in the silver-containing composite slurry and prevent crack propagation. This is because when cracks extend to the position of the organic microspheres, they will be intercepted by the organic microspheres and will not continue to extend.

[0048] Furthermore, the present invention also provides a method for preparing a silver-containing composite slurry, comprising the following steps:

[0049] Prepare the raw materials of the silver-containing composite paste according to the above;

[0050] Mixing the metallic silver, the auxiliary agent and the organic microspheres to prepare a premix;

[0051] The above premix is ​​placed in a vacuum of 10 -3 Pa to 10 3 Pa environment, and stir until the viscosity of the premix is ​​10 Pa·s to 100 Pa·s.

[0052] In a specific example, mixing the metallic silver, the additive, and the organic microspheres to prepare a premix includes:

[0053] Mixing metallic silver, organic microspheres and an organic solvent, stirring, and preparing a liquid mixture;

[0054] Mix the liquid mixture, thickener, dispersant and defoamer and disperse evenly.

[0055] In a specific example, the liquid mixture, the thickener, the dispersant and the defoamer are mixed and dispersed in a high-speed disperser at a speed of 2000 rpm to 4000 rpm for 5 min to 15 min.

[0056] Further, the premix is ​​placed in a vacuum chamber at a temperature of 0°C to 5°C and a degree of vacuum of 10 -3 Pa to 10 3 Stirring is carried out in an environment of Pa.

[0057] The present invention further provides an electronic interconnection material, comprising the silver-containing composite slurry after calcination.

[0058] In a specific example, during the calcination process, the calcination temperature is 150° C. to 250° C., and the calcination time is 1 h to 3 h.

[0059] The silver-containing composite slurry contains organic microspheres, additives, and metallic silver composed of micron silver particles and nano silver particles. Since the organic microspheres occupy a certain fixed volume, the shrinkage degree of the silver paste during the sintering process can be further reduced, and the shrinkage stress in the sintered body can be improved. Since the modulus of the organic microspheres is smaller than that of silver, the stress problem caused by the inconsistent thermal expansion coefficient between the electronic interconnection material containing the silver-containing composite slurry and the substrate can be improved. The addition of the organic microspheres can further hinder cracks in the silver-containing composite slurry and prevent cracks from spreading.

[0060] The following specific examples are provided to further illustrate the silver-containing composite slurry and its preparation method of the present invention. The raw materials involved in the following specific embodiments, unless otherwise specified, can all be sourced from commercial sources. The organic microspheres composed of organic silica gel were purchased from Suzhou Zhiyi Microsphere Technology Co., Ltd., with a brand name of Si-3. Polyimide microspheres were prepared by precipitation polymerization. Epoxy resin microspheres were prepared by emulsion polymerization.

[0061] Example 1

[0062] This embodiment provides a silver-containing composite slurry, which is composed of the following raw materials, calculated by weight: 45 parts of micron silver particles, 40 parts of nano silver particles, 3 parts of organic solvent, 0.3 parts of thickener, 0.5 parts of dispersant and 4 parts of organic microspheres.

[0063] The average particle size of the micron silver particles is 5 μm, the average particle size of the nano silver particles is 100 nm, the organic solvent is ethylene glycol, the thickener is polyvinyl alcohol, the dispersant is sodium dodecyl sulfate, the composition of the organic microspheres is polyimide, and the particle size of the organic microspheres is 3 μm.

[0064] The preparation method of the silver-containing composite slurry comprises: adding organic microspheres, micron silver particles and nano silver particles into an organic solvent, ultrasonically and synchronously stirring, so that the organic microspheres and metallic silver powder are evenly dispersed in the organic solvent; adding a thickener and a dispersant into the liquid mixture, using a high-speed disperser to disperse the mixture at a speed of 3000 rpm for 10 minutes; placing the liquid mixture at a temperature of 0°C to 5°C and a vacuum degree of 10 -3 Pa to 10 3 Pa environment, and continue stirring to evaporate the excess solvent and adjust the slurry viscosity to the range of 16 to 18 Pa·s.

[0065] Example 2

[0066] This embodiment provides a silver-containing composite slurry, which is composed of the following raw materials in parts by weight: 45 parts of micron silver particles, 40 parts of nano silver particles, 3 parts of organic solvent, 0.3 parts of thickener, 0.5 parts of dispersant and 4 parts of organic microspheres.

[0067] The average particle size of the micron silver particles is 5 μm, the average particle size of the nano silver particles is 10 nm, the organic solvent is ethylene glycol, the thickener is polyvinyl alcohol, the dispersant is sodium dodecyl sulfate, the composition of the organic microspheres is polyimide, and the particle size of the organic microspheres is 5 μm.

[0068] The preparation method of the silver-containing composite slurry comprises: adding organic microspheres, micron silver particles and nano silver particles into an organic solvent, ultrasonically and synchronously stirring, so that the organic microspheres and metallic silver powder are evenly dispersed in the organic solvent; adding a thickener and a dispersant into the liquid mixture, using a high-speed disperser to disperse the mixture at a speed of 3000 rpm for 10 minutes; placing the liquid mixture at a temperature of 0°C to 5°C and a vacuum degree of 10 -3 Pa to 10 3 Pa environment, and continue stirring to evaporate the excess solvent and adjust the slurry viscosity to the range of 16 to 18 Pa·s.

[0069] Example 3

[0070] This embodiment provides a silver-containing composite slurry, which is composed of the following raw materials in parts by weight: 52 parts of micron silver particles, 38 parts of nano silver particles, 2 parts of organic solvent, 0.4 parts of thickener, 0.4 parts of dispersant and 6 parts of organic microspheres.

[0071] The average particle size of the micron silver particles is 3 μm, the average particle size of the nano silver particles is 80 nm, the organic solvent is ethylene glycol, the thickener is polyvinyl alcohol, the dispersant is sodium dodecyl sulfate, the composition of the organic microspheres is organic silica gel, and the particle size of the organic microspheres is 3 μm.

[0072] The preparation method of the silver-containing composite slurry comprises: adding organic microspheres, micron silver particles and nano silver particles into an organic solvent, ultrasonically and synchronously stirring, so that the organic microspheres and metallic silver powder are evenly dispersed in the organic solvent; adding a thickener and a dispersant into the liquid mixture, using a high-speed disperser to disperse the mixture at a speed of 3000 rpm for 10 minutes; placing the liquid mixture at a temperature of 0°C to 5°C and a vacuum degree of 10 -3 Pa to 10 3 Pa environment, and continue stirring to evaporate the excess solvent and adjust the slurry viscosity to the range of 16 to 18 Pa·s.

[0073] Example 4

[0074] This embodiment provides a silver-containing composite slurry, which is composed of the following raw materials in parts by weight: 50 parts of micron silver particles, 40 parts of nano silver particles, 2 parts of organic solvent, 0.4 parts of thickener, 0.4 parts of dispersant and 6 parts of organic microspheres.

[0075] The average particle size of the micron silver particles is 10 μm, the average particle size of the nano silver particles is 50 nm, the organic solvent is ethylene glycol, the thickener is polyvinyl alcohol, the dispersant is sodium dodecyl sulfate, the composition of the organic microspheres is organic silica gel, and the particle size of the organic microspheres is 5 μm.

[0076] The preparation method of the silver-containing composite slurry comprises: adding organic microspheres, micron silver particles and nano silver particles into an organic solvent, ultrasonically and synchronously stirring, so that the organic microspheres and metallic silver powder are evenly dispersed in the organic solvent; adding a thickener and a dispersant into the liquid mixture, using a high-speed disperser to disperse the mixture at a speed of 3000 rpm for 10 minutes; placing the liquid mixture at a temperature of 0°C to 5°C and a vacuum degree of 10 -3 Pa to 10 3 Pa environment, and continue stirring to evaporate the excess solvent and adjust the slurry viscosity to the range of 16 to 18 Pa·s.

[0077] Comparative Example 1

[0078] The comparative example provides a silver-containing composite slurry, which is composed of the following raw materials in parts by weight: 45 parts of micron silver particles, 40 parts of nano silver particles, 3 parts of organic solvent, 0.3 parts of thickener and 0.5 parts of dispersant.

[0079] The average particle size of the micron silver particles is 5 μm, the average particle size of the nano silver particles is 100 nm, the organic solvent is ethylene glycol, the thickener is polyvinyl alcohol, and the dispersant is sodium dodecyl sulfate.

[0080] The preparation method of the silver-containing composite slurry comprises: adding micron silver particles and nano silver particles to an organic solvent, ultrasonically stirring simultaneously; adding a thickener and a dispersant to the liquid mixture, and dispersing the mixture at a speed of 3000 rpm for 10 minutes using a high-speed disperser; placing the liquid mixture at a temperature of 0°C to 5°C and a vacuum degree of 10 -3 Pa to 10 3 Pa environment, and continue stirring to evaporate the excess solvent and adjust the slurry viscosity to the range of 16 to 18 Pa·s.

[0081] Comparative Example 2

[0082] The comparative example provides a silver-containing composite slurry, which is composed of the following raw materials in parts by weight: 45 parts of micron silver particles, 40 parts of nano silver particles, 3 parts of organic solvent, 0.3 parts of thickener, 0.5 parts of dispersant and 4 parts of organic microspheres.

[0083] The average particle size of the micron silver particles is 5 μm, the average particle size of the nano silver particles is 100 nm, the organic solvent is ethylene glycol, the thickener is polyvinyl alcohol, the dispersant is sodium dodecyl sulfate, the composition of the organic microspheres is epoxy resin, and the particle size of the organic microspheres is 3 μm.

[0084] The preparation method of the silver-containing composite slurry comprises: adding organic microspheres, micron silver particles and nano silver particles into an organic solvent, ultrasonically and synchronously stirring, so that the organic microspheres and metallic silver powder are evenly dispersed in the organic solvent; adding a thickener and a dispersant into the liquid mixture, using a high-speed disperser to disperse at a speed of 3000 rpm for 10 minutes; placing the liquid mixture at a temperature of 0°C to 5°C and a vacuum degree of 10 -3 Pa to 10 3 Pa environment, and continue stirring to evaporate the excess solvent and adjust the slurry viscosity to the range of 16 to 18 Pa·s.

[0085] Comparative Example 3

[0086] The comparative example provides a silver-containing composite slurry, which is composed of the following raw materials by weight: 45 parts of micron silver particles, 40 parts of nano silver particles, 3 parts of organic solvent, 0.3 parts of thickener, 0.5 parts of dispersant and 20 parts of organic microspheres.

[0087] The average particle size of the micron silver particles is 5 μm, the average particle size of the nano silver particles is 100 nm, the organic solvent is ethylene glycol, the thickener is polyvinyl alcohol, the dispersant is sodium dodecyl sulfate, the composition of the organic microspheres is polyimide, and the particle size of the organic microspheres is 3 μm.

[0088] The preparation method of the silver-containing composite slurry comprises: adding organic microspheres, micron silver particles and nano silver particles into an organic solvent, ultrasonically and synchronously stirring, so that the organic microspheres and metallic silver powder are evenly dispersed in the organic solvent; adding a thickener and a dispersant into the liquid mixture, using a high-speed disperser to disperse the mixture at a speed of 3000 rpm for 10 minutes; placing the liquid mixture at a temperature of 0°C to 5°C and a vacuum degree of 10 -3 Pa to 10 3 Pa environment, and continue stirring to evaporate the excess solvent and adjust the slurry viscosity to the range of 16 to 18 Pa·s.

[0089] Performance test: The obtained silver-containing composite slurry was coated on a gold-plated CPC (copper-molybdenum-copper-copper) heat sink by screen printing, and a silicon chip was attached to the silver-containing composite slurry and sintered at 200°C in an air atmosphere for 2 hours.

[0090]

[0091] By comparing Comparative Example 1 with Example 1, it can be seen that adding polymer microspheres can effectively reduce the Young's modulus of the silver-containing composite slurry, alleviate the stress problem caused by thermal mismatch, and effectively improve the delamination phenomenon after thermal cycling.

[0092] In addition, in comparison between Comparative Example 2 and Example 1, since polymer microspheres with poor heat resistance were used, the microspheres were thermally decomposed at high temperatures, which affected the sintering performance of the silver-containing composite slurry and resulted in poor sintering.

[0093] In addition, in comparison between Comparative Example 3 and Example 1, since too many organic microspheres were used, too much of the interface between silver and the substrate was occupied, which significantly affected the bonding performance of the sintered silver and caused stratification after temperature cycling.

[0094] The above-mentioned silver-containing composite slurry contains organic microspheres, additives, and metallic silver composed of micron silver particles and nano silver particles. Since the organic microspheres occupy a certain fixed volume, the shrinkage degree of the silver paste during the sintering process can be reduced, and the shrinkage stress in the sintered body can be improved. In addition, by adding organic microspheres, since the modulus of the organic microspheres is smaller than that of silver, the modulus of the composite material as a whole after sintering can be reduced, and the stress is smaller under the same strain. Therefore, the stress problem caused by the inconsistent thermal expansion coefficient between the electronic interconnect material containing the silver-containing composite slurry and the substrate can be improved. The addition of the above-mentioned organic microspheres can further play a role in hindering cracks in the silver-containing composite slurry and prevent crack propagation.

[0095] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0096] The above-described embodiments only express several implementation methods of the present invention, which are convenient for understanding the technical solutions of the present invention in detail, but they cannot be understood as limiting the scope of protection of the invention patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. It should be understood that the technical solutions obtained by those skilled in the art through logical analysis, reasoning or limited experiments on the basis of the technical solutions provided by the present invention are all within the protection scope of the claims attached to the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the contents of the attached claims, and the description can be used to interpret the contents of the claims.

Claims

1. A silver-containing composite slurry, characterized in that: The raw materials include, by weight: 60-95 parts of metallic silver, 1-10 parts of additives and 1-15 parts of organic microspheres; The metallic silver comprises micron silver particles and nano silver particles in a mass ratio of 0.5:5 to 5:1, the particle size of the nano silver particles is 5nm to 900nm, and the particle size of the micron silver particles is 1μm to 20μm. The organic microspheres are composed of at least one of organic silica gel, polyimide resin and poly(p-phenylene terephthalamide), and the pyrolysis temperature of the organic microspheres is 300° C. to 500° C.

2. The silver-containing composite slurry according to claim 1, characterized in that: The auxiliary agent includes an organic solvent, a thickener and a dispersant in a weight ratio of (2~3): (0.1~0.6): (0.2~0.8).

3. The silver-containing composite slurry according to claim 2, characterized in that: The organic solvent is selected from at least one of ethanol, ethylene glycol, propylene glycol, glycerol, butanol, polyethylene glycol, butyl carbitol, toluene, xylene, phenol, tributyl phosphate, amyl acetate, tetraethylene glycol butyl ether, triethylene glycol butyl ether, and terpineol.

4. The silver-containing composite slurry according to claim 2, characterized in that: The thickener is selected from at least one of polyethylene glycol, hydroxyethyl cellulose, ethyl cellulose and polyvinyl alcohol.

5. The silver-containing composite slurry according to claim 2, characterized in that: The dispersant is selected from at least one of ethyl acetate, sodium lauryl sulfate, polyvinyl amide, polyacrylamide, fish oil and soybean lecithin.

6. The silver-containing composite slurry according to any one of claims 1 to 5, characterized in that: The organic microspheres have at least one of the following characteristics: (1) The particle size of the organic microspheres is 0.5 μm to 20 μm; (2) The Young's modulus of the organic microspheres is 0.2 GPa to 10 GPa.

7. A method for preparing a silver-containing composite slurry, characterized in that: The following steps are involved: Preparation of raw materials for the silver-containing composite slurry according to any one of claims 1 to 6; Mixing the metallic silver, the auxiliary agent and the organic microspheres to prepare a premix; The premix is ​​placed in a vacuum of 10 -3 Pa to 10 3 Pa environment, and stirring is performed until the viscosity of the premix is ​​10 Pa·s~100 Pa·s.

8. The method for preparing the silver-containing composite slurry according to claim 7, characterized in that: Mixing the metallic silver, the auxiliary agent and the organic microspheres to prepare a premix comprises: Mixing the metallic silver, the organic microspheres and the organic solvent, stirring, and preparing a liquid mixture; The liquid mixture, thickener and dispersant are mixed and dispersed uniformly.

9. An electronic interconnection material, characterized in that: The invention comprises the silver-containing composite slurry as claimed in any one of claims 1 to 6 after calcination.

10. The electronic interconnect material according to claim 9, characterized in that In the calcination treatment, the calcination temperature is 150°C to 250°C.

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