WO2022227736A1 - 一种纳米银膏及其制备方法 - Google Patents

一种纳米银膏及其制备方法 Download PDF

Info

Publication number
WO2022227736A1
WO2022227736A1 PCT/CN2022/073665 CN2022073665W WO2022227736A1 WO 2022227736 A1 WO2022227736 A1 WO 2022227736A1 CN 2022073665 W CN2022073665 W CN 2022073665W WO 2022227736 A1 WO2022227736 A1 WO 2022227736A1
Authority
WO
WIPO (PCT)
Prior art keywords
nano
silver paste
silver
powder
average particle
Prior art date
Application number
PCT/CN2022/073665
Other languages
English (en)
French (fr)
Inventor
蔡航伟
杜昆
许四妹
Original Assignee
广州汉源微电子封装材料有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 广州汉源微电子封装材料有限公司 filed Critical 广州汉源微电子封装材料有限公司
Priority to JP2023559032A priority Critical patent/JP2024512617A/ja
Publication of WO2022227736A1 publication Critical patent/WO2022227736A1/zh
Priority to US18/468,587 priority patent/US20240009731A1/en

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
    • H01B1/20—Conductive material dispersed in non-conductive organic material
    • H01B1/22—Conductive material dispersed in non-conductive organic material the conductive material comprising metals or alloys
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
    • B22F1/05—Metallic powder characterised by the size or surface area of the particles
    • B22F1/054—Nanosized particles
    • B22F1/0545—Dispersions or suspensions of nanosized particles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
    • B22F1/05—Metallic powder characterised by the size or surface area of the particles
    • B22F1/052—Metallic powder characterised by the size or surface area of the particles characterised by a mixture of particles of different sizes or by the particle size distribution
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
    • B22F1/10—Metallic powder containing lubricating or binding agents; Metallic powder containing organic material
    • B22F1/103—Metallic powder containing lubricating or binding agents; Metallic powder containing organic material containing an organic binding agent comprising a mixture of, or obtained by reaction of, two or more components other than a solvent or a lubricating agent
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
    • B22F1/10—Metallic powder containing lubricating or binding agents; Metallic powder containing organic material
    • B22F1/107—Metallic powder containing lubricating or binding agents; Metallic powder containing organic material containing organic material comprising solvents, e.g. for slip casting
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
    • B22F1/14—Treatment of metallic powder
    • B22F1/145—Chemical treatment, e.g. passivation or decarburisation
    • B22F1/147—Making a dispersion
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K35/00—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
    • B23K35/02—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by mechanical features, e.g. shape
    • B23K35/0222—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by mechanical features, e.g. shape for use in soldering, brazing
    • B23K35/0244—Powders, particles or spheres; Preforms made therefrom
    • B23K35/025—Pastes, creams, slurries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B13/00—Apparatus or processes specially adapted for manufacturing conductors or cables
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F7/00—Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression
    • B22F7/02—Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression of composite layers
    • B22F7/04—Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression of composite layers with one or more layers not made from powder, e.g. made from solid metal
    • B22F2007/042—Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression of composite layers with one or more layers not made from powder, e.g. made from solid metal characterised by the layer forming method
    • B22F2007/047—Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression of composite layers with one or more layers not made from powder, e.g. made from solid metal characterised by the layer forming method non-pressurised baking of the paste or slurry containing metal powder
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F2301/00—Metallic composition of the powder or its coating
    • B22F2301/25—Noble metals, i.e. Ag Au, Ir, Os, Pd, Pt, Rh, Ru
    • B22F2301/255—Silver or gold
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F2301/00—Metallic composition of the powder or its coating
    • B22F2301/30—Low melting point metals, i.e. Zn, Pb, Sn, Cd, In, Ga
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F2304/00—Physical aspects of the powder
    • B22F2304/05—Submicron size particles
    • B22F2304/054—Particle size between 1 and 100 nm
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F2304/00—Physical aspects of the powder
    • B22F2304/05—Submicron size particles
    • B22F2304/056—Particle size above 100 nm up to 300 nm
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F2304/00—Physical aspects of the powder
    • B22F2304/05—Submicron size particles
    • B22F2304/058—Particle size above 300 nm up to 1 micrometer
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F2304/00—Physical aspects of the powder
    • B22F2304/10—Micron size particles, i.e. above 1 micrometer up to 500 micrometer
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F7/00—Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression
    • B22F7/06—Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression of composite workpieces or articles from parts, e.g. to form tipped tools
    • B22F7/062—Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression of composite workpieces or articles from parts, e.g. to form tipped tools involving the connection or repairing of preformed parts

Definitions

  • the invention relates to the technical field of electronic component packaging, in particular to a nano-silver paste and a preparation method thereof.
  • the new generation of power semiconductors represented by silicon carbide and gallium nitride have the characteristics of wide band gap, high breakdown voltage, strong thermal stability, and stable switching characteristics. They are widely used in rail transit, aerospace, new energy vehicles, Deep sea and deep well exploration and other fields.
  • Nano-silver paste has become the most potential low-temperature sealing interconnect material due to its good electrical and thermal conductivity, low-temperature sealing, high reliability and high-temperature service performance.
  • the original stacking density of the nano-silver paste is low.
  • the sealing layer is prone to cracks during pressure-free sealing, resulting in a decrease in the interface welding rate, low mechanical strength, and a significant decrease in electrical and thermal conductivity compared to bulk silver. Moreover, due to the large thermal expansion coefficient of the sealing silver paste, a large thermomechanical stress will also be generated during the service process, resulting in the failure of the sealing part.
  • the primary purpose of the present invention is to overcome the shortcomings and deficiencies of the prior art, and to provide a nano-silver paste to solve the problem of low stacking density of the sealing layer, severe volume shrinkage, and easy occurrence of the existing nano-silver paste during pressureless sealing. Cracks, low interface welding rate, and then improve the mechanical properties and reliability of the sealing part.
  • Another object of the present invention is to provide a method for preparing the above-mentioned nano-silver paste.
  • the first object of the present invention is achieved through the following technical solutions: a nano-silver paste, comprising nano-silver powder, micron tin-based solder powder, reducing agent, dispersant, and diluent.
  • the material of the micron tin-based solder powder is a tin-based alloy with a melting point in the range of 120-250 ° C; preferably SnBi series alloys, SnBiAg series alloys, SnAg series alloys, SnCu series alloys, SnAgCu series alloys, SnSb series alloys, At least one of SnSbCu series alloys, SnSbAg series alloys, SnAgCuBi series alloys, and SnAgCuSb series alloys.
  • the average particle size of the nano-silver powder is 5-3000 nm.
  • the average particle size of the nano-silver powder is 10-1500 nm.
  • the nano-silver powder is a nano-silver powder with an average particle size or a mixture of two or more nano-silver powders with different average particle sizes.
  • the average particle size of the micron tin-based solder powder is 0.1-100 ⁇ m.
  • the average particle size of the micron tin-based solder powder is 0.5-50 ⁇ m.
  • the mass ratio of the nano silver powder to the micron tin-based solder powder is 20-500:1.
  • the mass ratio of the nano silver powder to the micron tin-based solder powder is 30-200:1.
  • the diluent is at least one of alcohols, hydrocarbons, ketones, esters and the like.
  • the mass percentage of the diluent in the system is 2-8%.
  • the mass percentage of the dispersant in the system is 0.1-3%.
  • the reducing agent is at least one of organic acids.
  • the mass percentage of the reducing agent in the system is 0.1-1.5%.
  • nano-silver paste The preparation method of the above-mentioned nano-silver paste: the nano-silver powder, the micron tin-based solder powder, the reducing agent, the dispersant and the diluent are uniformly mixed to obtain the nano-silver paste.
  • the nano silver powder is obtained by chemically reducing the silver salt solution and drying the silver deposition layer in a negative pressure environment below 100Pa.
  • the micron tin-based solder powder is obtained by grinding the tin-based solder through a vacuum grinder.
  • the uniform mixing is preferably by means of mechanical stirring or magnetic stirring.
  • micron tin-based solder powder with low melting point in the nano-silver paste if the amount added is too small, it is not enough to fill the pores between the nano-silver particles that are not completely melted; if the amount is too much, the sealing layer after welding There are too many low-melting phase phases in it, which will reduce the reliability of the sealing layer after sealing. Therefore, controlling the amount of the low-melting micron tin-based solder powder in the nano-silver paste is one of the keys of the present invention.
  • Micron tin-based solder powder with low melting point if the particle size is too small, on the one hand, the smaller the particle size, the larger the specific surface area, the easier the powder particles are oxidized; on the other hand, the smaller the particle size, the higher the cost of manufacturing the powder particles. However, if the particle size is too large, the contact probability with the nano-silver powder in the nano-silver paste will be reduced, which is not conducive to the full mixing of the micron tin-based solder powder in the nano-silver paste.
  • Alcohols, hydrocarbons, ketones, esters, etc. are used as diluents, and when the mass percentage of the diluent in the whole nano-silver paste system is 2%-8%, the diluent, micron tin-based solder powder and nanometer The silver powder mixes well and produces a paste-like paste product of moderate viscosity. When the amount of diluent added is too small, the viscosity is high, and a paste-like slurry product cannot be formed. 's mounting.
  • Polyhydrocarbon amides, polyhydrocarbon acid salts, alkyl acid salts, etc. are used as dispersants, and when the mass percentage of the dispersants in the whole nano-silver paste system is 0.1%-3%, it can make the micron tin-based solder powder and The nano-silver powder is uniformly dispersed. When the amount of dispersant added is too small, it is not conducive to the uniform dispersion of micron tin-based solder powder and nano-silver powder, which will cause agglomeration.
  • the organic acid When used as a reducing agent, and the mass percentage of the reducing agent in the whole nano-silver paste system is 0.1%-1.5%, it can effectively remove the oxides on the surface of the micron tin-based solder powder and the nano-silver powder during the sealing process .
  • the amount of reducing agent added is too small, it is difficult to mix the reducing agent, micron tin-based solder powder and nano-silver powder evenly. The oxide layer on the surface of tin-based solder powder and nano-silver powder is fully and effectively removed.
  • the present invention has the following beneficial effects:
  • the nano-silver paste of the present invention is evenly mixed with low-melting micron tin-based solder powder, and the completely melted micron tin-based solder powder during the sealing process fills the pores between the incompletely melted nano-silver particles, thereby solving the problem of
  • the existing nano-silver paste has the problems of low stacking density, high porosity, severe volume shrinkage, easy occurrence of cracks and low interface welding rate during pressureless sealing, thereby improving the mechanical properties and reliability of the sealing part.
  • the preparation method of the nano-silver paste of the present invention is based on large-scale production, and has the advantages of simple process, low cost, strong operability, mass production, and remarkable economic benefit.
  • the nano-silver paste contains nano-silver powder with an average particle size of 30 nm and Sn42Bi58 alloy powder with an average particle size of 5 ⁇ m (melting point at 139° C.), and the powder particles are formed into a paste. It is a diluent for the silver paste, a dispersant to prevent the powder agglomeration in the silver paste, and a reducing agent for reducing the oxide layer of the soldered surface and the oxide layer of the metal particles in the silver paste during the sealing process.
  • the mass ratio of the nanometer silver powder to the micron Sn42Bi58 alloy powder is 200:1.
  • the diluent is ethylene glycol and n-butane with a mass percentage of 1:2, and the mass percentage of the diluent in the entire nano-silver paste system is 2%.
  • the dispersant is potassium dodecyl sulfate and sodium polybutenoate with a mass percentage of 3:1, and the mass percentage of the dispersant in the entire nano-silver paste system is 1.2%.
  • the reducing agent is rosin acid and acetic acid with a mass percentage of 1:4, and the mass percentage of the reducing agent in the entire nano-silver paste system is 0.5%.
  • the preparation method of nano silver paste comprises the following steps:
  • S2 configure the Sn42Bi58 alloy according to the alloy composition of the tin-based solder (mass percentage of Sn and Bi (42:58)), and grind the Sn42Bi58 alloy by a vacuum grinder to obtain Sn42Bi58 alloy powder with an average particle size of 5 ⁇ m;
  • the total mass percentage in the whole nano-silver paste system is 2%, and the diluent is prepared.
  • the mass percentage of potassium dodecyl sulfate and sodium polybutenoate of 3:1 the total mass percentage in the whole nano-silver paste system is 1.2%, and the dispersant is prepared.
  • the ratio of rosin acid and acetic acid whose mass percentage is 1:4 the total mass percentage in the whole nano-silver paste system is 0.5%, and the reducing agent is prepared.
  • step S4 the nano-silver powder made in step S1 and the micron Sn42Bi58 powder made in step S2 are added to the mixed solvent containing reducing agent, dispersant and diluent prepared in step S3 according to the mass ratio of 200:1, using Mechanically stirring and uniformly mixing to obtain nano-silver paste mixed with micron tin-based solder powder particles.
  • the nano-silver paste contains a mixed nano-silver powder composed of nano-silver powder with an average particle size of 20 nm and nano-silver powder with an average particle size of 100 nm, and the mass ratio is 5:3; Sn96.5Ag3.5 alloy powder with a particle size of 10 ⁇ m (melting point is 221°C), the mass ratio of mixed nano-silver powder and micron Sn96.5Ag3.5 alloy powder is 160:1; and the above powder is formed into a paste It is a diluent in the form of a thin film, a dispersant to prevent the agglomeration of powder in the silver paste, and a reducing agent used to reduce the oxide layer of the soldered surface and the oxide layer of the metal particles in the silver paste during the sealing process.
  • the diluent is hexanone and n-pentane with a mass percentage of 3:2, and the mass percentage of the diluent in the entire nano-silver paste system is 3.5%.
  • the dispersant is polyvinylamide and potassium polyacrylate with a mass percentage of 4:3, and the mass percentage of the dispersant in the entire nano-silver paste system is 1.9%.
  • the reducing agent is oxalic acid and adipic acid with a mass percentage of 2:1, and the mass percentage of the reducing agent in the entire nano-silver paste system is 0.8%.
  • the preparation method of nano silver paste comprises the following steps:
  • the nano-silver powder made in step S1 (the mass percentage of nano-silver powder with an average particle size of 20 nm and a nano-silver powder with an average particle size of 100 nm is 5:3) and the micron Sn96.5Ag3.5 alloy powder made in step S2
  • the particles are added to the mixed solvent containing reducing agent, dispersant and diluent prepared in step S3, and uniformly mixed by magnetic stirring to obtain nano-silver paste mixed with micron tin-based solder powder particles.
  • the nano-silver paste contains a mixed nano-silver powder composed of nano-silver powder with an average particle size of 10 nm, nano-silver powder with an average particle size of 120 nm, and nano-silver powder with an average particle size of 800 nm, Its mass ratio is 7:4:1; it contains Sn99.3Cu0.7 alloy powder with an average particle size of 15 ⁇ m (melting point is 227°C), and the mass ratio of mixed nano-silver powder and micron Sn99.3Cu0.7 alloy powder is 120:1; and contains a diluent for forming the above powder into a paste, a dispersant for preventing powder agglomeration in the silver paste, and a reducing agent for reducing the oxide layer of the soldered surface and the oxide layer of the metal particles in the silver paste during the sealing process .
  • the diluent is n-pentane and ethyl acetate with a mass percentage of 2:5, and the mass percentage of the diluent in the entire nano-silver paste system is 5%.
  • the dispersing agent is polyacrylamide and sodium lauryl sulfate with a mass percentage of 1:3, and the mass percentage of the dispersing agent in the entire nano-silver paste system is 2.2%.
  • the reducing agent is glutaric acid and rosin acid whose mass percentage is 3:1, and the mass percentage of the reducing agent in the whole nano-silver paste system is 1%.
  • the preparation method of nano silver paste comprises the following steps:
  • step S4 the nano silver powder made in step S1 (the nano silver powder with an average particle size of 10 nm, the nano silver powder with an average particle size of 120 nm, and the nano silver powder with an average particle size of 800 nm in a mass ratio of 7:4:1) and step S2
  • the prepared micron Sn99.3Cu0.7 alloy powder is added to the mixed solvent containing the reducing agent, dispersant and diluent prepared in step S3 according to the mass ratio of 120:1, and uniformly mixed by mechanical stirring to obtain a mixed solvent.
  • Nano-silver paste with micron tin-based solder powder is added to the mixed solvent containing the reducing agent, dispersant and diluent prepared in step S3 according to the mass ratio of 120:1, and uniformly mixed by mechanical stirring to obtain a mixed solvent.
  • the nano-silver paste contains a mixed nano-silver powder composed of nano-silver powder with an average particle size of 25 nm, nano-silver powder with an average particle size of 70 nm, and nano-silver powder with an average particle size of 1200 nm, Its mass ratio is 9:5:1; it contains Sn42Bi57Ag1 alloy powder with an average particle size of 20 ⁇ m (melting point is 139°C) and Sn96.5Ag3Cu0.5 alloy powder (melting point is 217°C) A mixed low melting point microalloy Powder (its mass ratio is 4:1), the mass ratio of above-mentioned mixed nano-silver powder and mixed low-melting-point micro-alloy powder is 30:1; The dispersant for powder agglomeration and the reducing agent for reducing the oxide layer of the soldered surface and the metal particle oxide layer in the silver paste during the sealing process.
  • the diluent is n-pentane, propylene glycol and ethyl acetate with a mass percentage of 1:3:4, and the mass percentage of the diluent in the entire nano-silver paste system is 8%.
  • the dispersing agent is polyvinylamide, sodium polyacrylate and sodium lauryl sulfate with a mass percentage of 1:2:4, and the mass percentage of the dispersing agent in the entire nano-silver paste system is 2.5%.
  • the reducing agent is oxalic acid and rosin acid with a mass percentage of 1:4, and the mass percentage of the reducing agent in the entire nano-silver paste system is 1.2%.
  • the preparation method of nano silver paste comprises the following steps:
  • Sn96.5Ag3Cu0.5 alloy and Sn42Bi57Ag1 alloy respectively according to the alloy composition of the tin-based solder, and grind the Sn42Bi57Ag1 alloy and the Sn96.5Ag3Cu0.5 alloy by a vacuum grinder, respectively, to obtain an average particle size of 20 ⁇ m.
  • step S4 the nano silver powder made in step S1 (the nano silver powder with an average particle size of 25 nm, the nano silver powder with an average particle size of 70 nm, and the nano silver powder with an average particle size of 1200 nm in a mass ratio of 9:5:1) and step S2
  • the prepared micro-alloy powder (the mass ratio of Sn42Bi57Ag1 alloy powder and Sn96.5Ag3Cu0.5 alloy powder is 4:1) is added to step S3 according to the mass ratio of 30:1, containing reducing agent, dispersant, In the mixed solvent of the diluent, magnetic stirring is used to uniformly mix to obtain a nano-silver paste mixed with micron tin-based solder powder particles.
  • This embodiment provides a nano-silver paste, which contains nano-silver powder with an average particle size of 15 nm, nano-silver powder with an average particle size of 60 nm, nano-silver powder with an average particle size of 900 nm, and nano-silver powder with an average particle size of 1500 nm.
  • the mixed nano-silver powder composed of nano-silver powder has a mass ratio of 12:9:5:1; it contains Sn64Bi35Ag1 alloy powder with an average particle size of 50 ⁇ m (melting point range is about 139-180°C), and Sn96Ag2 with an average particle size of 10 ⁇ m .5Bi1Cu0.5 alloy powder (melting point is about 215°C) and SnSb5 alloy powder with an average particle size of 2 ⁇ m (melting point is about 240°C) is a mixed low-melting micro-alloy powder with a mass ratio of 11:5 : 2; the mass ratio of the above-mentioned mixed nano-silver powder and the mixed low-melting-point micro-alloy powder is 80:1; and the above-mentioned powder is formed into a paste-like diluent, a dispersant, a sealing agent that prevents the powder from agglomerating in the silver paste The process is used to reduce the oxide layer of
  • the diluent is n-heptane, butanol and ethyl acetate with a mass percentage of 1:2:5, and the mass percentage of the diluent in the entire nano-silver paste system is 6%.
  • the dispersing agent is potassium polyacrylate, polyacrylamide and sodium lauryl sulfate with a mass percentage of 1:1:2, and the mass percentage of the dispersing agent in the entire nano-silver paste system is 3%.
  • the reducing agent is acetic acid, glutaric acid and rosin acid whose mass percentage is 1:3:4, and the mass percentage of the reducing agent in the whole nano-silver paste system is 1.5%.
  • the preparation method of nano silver paste comprises the following steps:
  • Sn64Bi35Ag1 alloy, Sn96Ag2.5Bi1Cu0.5 alloy and SnSb5 alloy according to the alloy composition of the tin-based solder, respectively, and grind them through a vacuum grinder to obtain Sn64Bi35Ag1 alloy powder with an average particle size of 50 ⁇ m.
  • the nano silver powder that the step S1 is made (average particle diameter is that the nano silver powder of 15nm, the nano silver powder that the average particle diameter is 60nm, the nano silver powder that the average particle diameter is 900nm, the average particle diameter is that the mass percent of the nano silver powder of 1500nm is 12:9:5:1) and the micro-alloy powder made in step S2 (the mass ratio of Sn64Bi35Ag1 alloy powder, Sn96Ag2.5Bi1Cu0.5 alloy powder and SnSb5 alloy powder is 11:5:2) according to 80:
  • the mass ratio of 1 is added to the mixed solvent containing reducing agent, dispersant and diluent prepared in step S3, and uniformly mixed by mechanical stirring to obtain nano-silver paste mixed with micron tin-based solder powder particles.
  • a sealing test is carried out on the nano-silver paste of the present invention as follows.
  • the testing samples and materials to be sealed required for the sealing test are as follows:
  • Embodiment 5 of the present invention nano-silver paste mixed with micron tin-based solder powder
  • Comparative Example 1 Nano-silver paste without micron tin-based solder powder (other conditions are the same as in Example 5 of the present invention)
  • Material to be sealed oxygen-free copper plate with a thickness of 1.5mm and a sealing area of 10mm*8mm.
  • the nano-silver paste of Comparative Example 1 or the nano-silver paste of Example 5 of the present invention is respectively sandwiched between two oxygen-free copper plates with a thickness of 0.1 mm, and the nano-silver paste of Comparative Example 1 and the present invention are implemented.
  • the nano-silver paste of Example 5 was simultaneously subjected to atmospheric pressure reflow sealing without additional pressure.
  • the performance test of the sealing layer after sealing is carried out below.
  • the performance test of the sealing layer includes the porosity, shear strength, thermal conductivity of the sealing layer, and the porosity of the sealing layer after being subjected to temperature cycle impact.
  • the porosity of the sealing layer is tested by an ultrasonic scanner or X-Ray detector, the shear strength is tested by an electronic universal testing machine, and the thermal conductivity is tested by a laser flash color thermal conductivity analyzer.
  • the greater the thermal conductivity of the sealing layer the stronger the ability of the sealing layer to conduct the heat generated during the operation of the power device.
  • the shear strength test was carried out on the five groups of sealing layers corresponding to each other after the sealing of the nano-silver paste of Comparative Example 1 and the nano-silver paste of Example 5 of the present invention, respectively.
  • the test results are shown in Table 2.
  • the sealing layer using the nano-silver paste of Comparative Example 1 and the nano-silver paste of Example 5 of the present invention is The degradation degree of the sealing layer of the nano-silver paste of the fifth embodiment of the invention is obviously lower than that of the nano-silver paste of the comparative example 1.
  • the degradation degree of the sealing layer of the nano-silver paste of the fifth embodiment of the present invention is lower than that of the comparative example
  • the nano-silver paste added with micron tin-based solder powders of different particle sizes and different addition amounts of the first embodiment of the present invention is used as a comparative example to conduct a sealing test.
  • the test samples and materials to be sealed required for the sealing test are as follows:
  • Test sample Nano-silver paste added with micron tin-based solder powder particles of different particle sizes and different addition amounts according to the first embodiment of the present invention
  • Embodiment 1 of the present invention according to the mass ratio of nano-silver powder and micron Sn42Bi58 powder with an average particle size of 5 ⁇ m as 200:1, the prepared nano-silver paste
  • Comparative Example 2 According to the ratio of the mass of the nano-silver powder to the micron Sn42Bi58 powder with an average particle size of 5 ⁇ m is 10:1 (other conditions are the same as those in the first embodiment of the present invention), the prepared nano-silver paste
  • Comparative Example 3 According to the ratio of the mass of the nano-silver powder to the micron Sn42Bi58 powder with an average particle size of 5 ⁇ m is 800:1 (other conditions are the same as the first embodiment of the present invention), the prepared nano-silver paste
  • Comparative Example 4 According to the ratio of the mass of the nano-silver powder to the micron Sn42Bi58 powder with an average particle size of 250 ⁇ m is 200:1 (other conditions are the same as those in the first embodiment of the present invention), the prepared nano-silver paste
  • Material to be sealed oxygen-free copper plate with a thickness of 1.5mm and a sealing area of 10mm*8mm.
  • the sealing layer after sealing with the nano-silver paste of Example 1, Comparative Example 2, Comparative Example 3 and Comparative Example 4 of the present invention has undergone 1000 times of temperature cycles of -40°C to 125°C. After the impact, the degradation degree of the sealing layer of the nano-silver paste of Example 1 of the present invention is significantly lower than that of the nano-silver paste of Comparative Example 2, Comparative Example 3, and Comparative Example 4.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Nanotechnology (AREA)
  • Dispersion Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Mechanical Engineering (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Manufacturing & Machinery (AREA)
  • Physics & Mathematics (AREA)
  • General Chemical & Material Sciences (AREA)
  • Powder Metallurgy (AREA)
  • Conductive Materials (AREA)
  • Manufacture Of Metal Powder And Suspensions Thereof (AREA)

Abstract

本发明公开了一种纳米银膏及其制备方法。本发明的纳米银膏包括纳米银粉、微米锡基焊料粉粒、还原剂、分散剂、稀释剂。本发明的纳米银膏是将纳米银粉、微米锡基焊料粉粒与还原剂、分散剂、稀释剂混合均匀得到。本发明的纳米银膏解决了现有技术中的纳米银膏在无压封接时堆垛密度低、孔隙率高、体积收缩剧烈、易出现裂纹、界面焊合率低的问题，从而提高了封接部位的力学性能与可靠性。

Description

一种纳米银膏及其制备方法 技术领域
本发明涉及电子元器件封装技术领域，特别是涉及一种纳米银膏及其制备方法。
背景技术
随着电子元器件日趋精密、微型化和集成化，势必导致封装密度与功率密度更高，因而会对封装的散热性和可靠性要求越来越高。以碳化硅、氮化镓为代表的新一代功率半导体，具有禁带宽度宽、击穿电压高、热稳定强、开关特性稳定等特点，被广泛应用于轨道交通、航空航天、新能源汽车、深海深井探测等领域。
在服役过程中，功率器件的互连材料会受到来自机械振动、热应力、高密度电流和功率循环等严苛考验，传统的锡基焊料已无法满足日益苛刻的可靠性要求，因此亟需开发新的耐高温封接材料和相应的封接工艺。
纳米金属颗粒由于具有高表面能、低熔点特性，近年来国内外提出使用纳米金属来封装元器件。纳米银膏因具有良好的导电导热性、低温封接性、高可靠性以及高温服役性能，成为目前最具潜力的低温封接互连材料。然而，纳米银膏原始堆垛密度较低，封接时，特别是封接器件的结构导致无法给予压力，或者为了防止压力对封接器件造成损伤而需要无压封接时，会产生大量不可控制的孔隙结构。封接层致密度低，体积收缩明显，在无压封接时封接层易出现裂纹，导致界面焊合率降低、机械强度低，导电导热性能相比于块体银大幅下降。而且，封接银膏因具有较大的热膨胀系数，在服役过程中也会产生较大的热机械应力，造成封接部位的失效。
发明内容
本发明的首要目的在于克服现有技术的缺点与不足，提供了一种纳米银膏，以解决现有纳米银膏在无压封接时封接层堆垛密度低、体 积收缩剧烈、易出现裂纹、界面焊合率低的问题，进而提高封接部位的力学性能与可靠性。
本发明的另一目的在于提供上述纳米银膏的制备方法。
本发明的第一目的通过下述技术方案实现：一种纳米银膏，包括纳米银粉、微米锡基焊料粉粒、还原剂、分散剂、稀释剂。
所述微米锡基焊料粉粒的材质为熔点在120-250℃范围内的锡基合金；优选为SnBi系列合金、SnBiAg系列合金、SnAg系列合金、SnCu系列合金、SnAgCu系列合金、SnSb系列合金、SnSbCu系列合金、SnSbAg系列合金、SnAgCuBi系列合金、SnAgCuSb系列合金中的至少一种。
所述纳米银粉的平均粒径为5-3000nm。
优选的，所述纳米银粉的平均粒径为10-1500nm。
所述纳米银粉为一种平均粒径的纳米银粉或两种以上不同平均粒径的纳米银粉混合体。
所述微米锡基焊料粉粒的平均粒径为0.1-100μm。
优选的，所述微米锡基焊料粉粒的平均粒径为0.5-50μm。
所述纳米银粉与所述微米锡基焊料粉粒的质量之比为20-500:1。
优选的，所述纳米银粉与所述微米锡基焊料粉粒的质量之比为30-200:1。
所述稀释剂为醇类、烃类、酮类、酯类等中的至少一种。
所述稀释剂在体系中的质量百分比为2-8％。
所述分散剂为聚烃类酰胺、聚烃类酸盐、烷基酸盐等中的至少一种。
所述分散剂在体系中的质量百分比为0.1-3％。
所述还原剂为有机酸中的至少一种。
所述还原剂在体系中的质量百分比为0.1-1.5％。
上述纳米银膏的制备方法：将所述纳米银粉、所述微米锡基焊料粉粒与所述还原剂、分散剂、稀释剂混合均匀，得到纳米银膏。
所述纳米银粉是通过化学还原银盐溶液，并将银沉积层在100Pa以下的负压环境中干燥的方法得到。
所述微米锡基焊料粉粒是将锡基焊料通过真空研磨机研磨得到。
所述混合均匀优选为采用机械搅拌或者磁力搅拌的方式。
纳米银膏中低熔点的微米锡基焊料粉粒，如果加入量太少，则不足以起到填充未完全熔化的纳米银颗粒间的孔隙的效果；如果加入量太多，焊后封接层中存在太多的低熔点相，反而会降低封接后封接层的可靠性。所以控制纳米银膏中低熔点微米锡基焊料粉粒的用量是本发明的关键之一。
低熔点的微米锡基焊料粉粒，如果粒径太小，一方面由于粒径越小，比表面积越大，粉粒越容易氧化；另一方面，粒径小，制造粉粒的成本高。但是如果粒径太大，与纳米银膏中的纳米银粉的接触几率会降低，不利于微米锡基焊料粉粒在纳米银膏中充分混合。
醇类、烃类、酮类、酯类等作为稀释剂，并且稀释剂在整个纳米银膏体系中的质量百分比为2％-8％时，能够使稀释剂、微米锡基焊料粉粒和纳米银粉混合均匀并产生粘性适中的膏状浆料产品。当稀释剂加入量过少时，粘性较大，无法形成膏状浆料产品，一方面不利于稀释剂、微米锡基焊料粉粒和纳米银粉混合均匀；另一方面不利于产品在封接面上的贴装。但当稀释剂加入量过大时，一方面粘性过小，产品在封接面上贴装时容易坍塌，不利于封接操作；另一方面，稀释剂过多，封接升温时，稀释剂挥发会产生过多气体，轻则会黏附在烧结炉的炉壁和管道内不好清理，重则会在封接层上产生大量空洞。
聚烃类酰胺、聚烃类酸盐、烷基酸盐等作为分散剂，并且分散剂在整个纳米银膏体系中的质量百分比为0.1％-3％时，能够使微米锡基焊料粉粒和纳米银粉分散均匀。当分散剂加入量过少时，不利于微米锡基焊料粉粒和纳米银粉分散均匀，会造成团聚。但当分散剂加入量过多时，一方面粘性过小，产品在封接面上贴装时容易坍塌，不利于封接操作；另一方面，分散剂过多，封接升温时，分散剂挥发会产生过多气体，轻则会黏附在烧结炉的炉壁和管道内不好清理，重则会在封接层上产生大量空洞。
有机酸作为还原剂，并且还原剂在整个纳米银膏体系中的质量百分比为0.1％-1.5％时，能够在封接过程中有效地将微米锡基焊料粉粒和纳米银粉表面的氧化物去除。当还原剂加入量过少时，还原剂、微米锡基焊料粉粒和纳米银粉很难混合均匀，很难保证微米锡基焊料粉粒 和纳米银粉能够充分有效的接触到还原剂，很难保证微米锡基焊料粉粒和纳米银粉表面的氧化层被充分有效的去除。但当还原剂加入量过多时，一方面粘性过小，产品在封接面上贴装时容易坍塌，不利于封接操作；另一方面，还原剂过多，封接升温时，还原剂挥发会产生过多酸性气体，轻则会黏附腐蚀烧结炉的炉壁和管道，重则会在封接层上产生大量空洞。
与现有技术相比，本发明具有以下有益效果：
1、本发明的纳米银膏中均匀混有低熔点微米锡基焊料粉粒，封接过程中完全熔化的微米锡基焊料粉粒填充了未完全熔化的纳米银颗粒间的孔隙，从而解决了现有纳米银膏在无压封接时堆垛密度低、孔隙率高、体积收缩剧烈、易出现裂纹、界面焊合率低的问题，进而提高了封接部位的力学性能与可靠性。
2、本发明的纳米银膏的制备方法以可规模化生产为出发点，工艺简单，成本低，可操作性强，可批量生产，经济效益显著。
具体实施方式
下面结合实施例，对本发明的具体实施方式作进一步详细描述。以下实施例用于说明本发明，但不用来限制本发明的范围。
实施例一
本实施例提供了一种纳米银膏，该纳米银膏中含有平均粒径为30nm的纳米银粉、平均粒径为5μm的Sn42Bi58合金粉粒(熔点为139℃)、将上述粉粒形成膏状的稀释剂、防止银膏中粉末发生团聚的分散剂、封接过程用于还原被焊面氧化层和银膏中金属颗粒氧化层的还原剂。所述纳米银粉与微米Sn42Bi58合金粉粒的质量之比为200:1。所述稀释剂为质量百分比为1:2的乙二醇和正丁烷，所述稀释剂在整个纳米银膏体系中的质量百分比为2％。所述分散剂为质量百分比为3:1的十二烷基硫酸钾和聚丁烯酸钠，所述分散剂在整个纳米银膏体系中的质量百分比为1.2％。所述还原剂为质量百分比为1:4的松香酸和乙酸，所述还原剂在整个纳米银膏体系中的质量百分比为0.5％。
纳米银膏的制备方法，包括如下步骤：
S1、通过化学还原银盐溶液，并采用将银沉积层在100Pa以下的负压环境中干燥的方法得到平均粒径为30nm的纳米银粉；
S2、按照锡基焊料的合金成分(Sn和Bi的质量百分比(42:58))配置好Sn42Bi58合金，将Sn42Bi58合金通过真空研磨机研磨，得到平均粒径为5μm的Sn42Bi58合金粉粒；
S3、按照质量百分比为1:2的乙二醇和正丁烷，在整个纳米银膏体系中的总质量百分比为2％的配比，配好稀释剂。按照质量百分比为3:1的十二烷基硫酸钾和聚丁烯酸钠，在整个纳米银膏体系中的总质量百分比为1.2％的配比，配好分散剂。按照质量百分比为1:4的松香酸和乙酸，在整个纳米银膏体系中的总质量百分比为0.5％的配比，配好还原剂。
S4、将步骤S1制成的纳米银粉与步骤S2制成的微米Sn42Bi58粉粒按照200:1的质量比，加入到步骤S3配好的含有还原剂、分散剂、稀释剂的混合溶剂中，采用机械搅拌均匀混合，得到混有微米锡基焊料粉粒的纳米银膏。
实施例二
本实施例提供了一种纳米银膏，该纳米银膏中含有平均粒径为20nm的纳米银粉、平均粒径为100nm的纳米银粉所组成的混合纳米银粉，其质量比为5:3；平均粒径为10μm的Sn96.5Ag3.5合金粉粒(熔点为221℃)，混合纳米银粉与微米Sn96.5Ag3.5合金粉粒的质量之比为160:1；并含有将上述粉粒形成膏状的稀释剂、防止银膏中粉末发生团聚的分散剂、封接过程用于还原被焊面氧化层和银膏中金属颗粒氧化层的还原剂。所述稀释剂为质量百分比为3:2的己酮和正戊烷，所述稀释剂在整个纳米银膏体系中的质量百分比为3.5％。所述分散剂为质量百分比为4:3的聚乙烯酰胺和聚丙烯酸钾，所述分散剂在整个纳米银膏体系中的质量百分比为1.9％。所述还原剂为质量百分比为2:1的草酸和己二酸，所述还原剂在整个纳米银膏体系中的质量百分比为0.8％。
纳米银膏的制备方法，包括如下步骤：
S1、通过化学还原银盐溶液，并采用将银沉积层在100Pa以下的负压环境中干燥的方法分别得到平均粒径为20nm和100nm的纳米银粉；
S2、按照锡基焊料的合金成分配置好所述的Sn96.5Ag3.5合金，将Sn96.5Ag3.5合金通过真空研磨机研磨，得到平均粒径为10μm的 Sn96.5Ag3.5合金粉粒；
S3、按照质量百分比为3:2的己酮和正戊烷，在整个纳米银膏体系中的总质量百分比为3.5％的配比，配好稀释剂。按照质量百分比为4:3的聚乙烯酰胺和聚丙烯酸钾，在整个纳米银膏体系中的总质量百分比为1.9％的配比，配好分散剂。按照质量百分比为2:1的草酸和己二酸，在整个纳米银膏体系中的总质量百分比为0.8％的配比，配好还原剂。
S4、将步骤S1制成的纳米银粉(平均粒径为20nm的纳米银粉、平均粒径为100nm的纳米银粉的质量百分比为5:3)与步骤S2制成的微米Sn96.5Ag3.5合金粉粒按照160:1的质量比，加入到步骤S3配好的含有还原剂、分散剂、稀释剂的混合溶剂中，采用磁力搅拌均匀混合，得到混有微米锡基焊料粉粒的纳米银膏。
实施例三
本实施例提供了一种纳米银膏，该纳米银膏中含有平均粒径为10nm的纳米银粉、平均粒径为120nm的纳米银粉、平均粒径为800nm的纳米银粉所组成的混合纳米银粉，其质量比为7:4:1；含有平均粒径为15μm的Sn99.3Cu0.7合金粉粒(熔点为227℃)，混合纳米银粉与微米Sn99.3Cu0.7合金粉粒的质量之比为120:1；并含有将上述粉粒形成膏状的稀释剂、防止银膏中粉末发生团聚的分散剂、封接过程用于还原被焊面氧化层和银膏中金属颗粒氧化层的还原剂。所述稀释剂为质量百分比为2:5的正戊烷和醋酸乙酯，所述稀释剂在整个纳米银膏体系中的质量百分比为5％。所述分散剂为质量百分比为1:3的聚丙烯酰胺和十二烷基硫酸钠，所述分散剂在整个纳米银膏体系中的质量百分比为2.2％。所述还原剂为质量百分比为3:1的戊二酸和松香酸，所述还原剂在整个纳米银膏体系中的质量百分比为1％。
纳米银膏的制备方法，包括如下步骤：
S1、通过化学还原银盐溶液，并采用将银沉积层在100Pa以下的负压环境中干燥的方法分别得到平均粒径为10nm、120nm、800nm的纳米银粉；
S2、按照锡基焊料的合金成分配置好所述的Sn99.3Cu0.7合金，将Sn99.3Cu0.7合金通过真空研磨机研磨，得到平均粒径为15μm的Sn99.3Cu0.7合金粉粒；
S3、按照质量百分比为2:5的正戊烷和醋酸乙酯，在整个纳米银膏体系中的总质量百分比为5％的配比，配好稀释剂。按照质量百分比为1:3的聚丙烯酰胺和十二烷基硫酸钠，在整个纳米银膏体系中的总质量百分比为2.2％的配比，配好分散剂。按照质量百分比为3:1的戊二酸和松香酸，在整个纳米银膏体系中的总质量百分比为1％的配比，配好还原剂。
S4、将步骤S1制成的纳米银粉(平均粒径为10nm的纳米银粉、平均粒径为120nm的纳米银粉、平均粒径为800nm的纳米银粉的质量比为7:4:1)与步骤S2制成的微米Sn99.3Cu0.7合金粉粒按照120:1的质量比，加入到步骤S3配好的含有还原剂、分散剂、稀释剂的混合溶剂中，采用机械搅拌均匀混合，得到混有微米锡基焊料粉粒的纳米银膏。
实施例四
本实施例提供了一种纳米银膏，该纳米银膏中含有平均粒径为25nm的纳米银粉、平均粒径为70nm的纳米银粉、平均粒径为1200nm的纳米银粉所组成的混合纳米银粉，其质量比为9:5:1；含有平均粒径为20μm的Sn42Bi57Ag1合金粉粒(熔点为139℃)和Sn96.5Ag3Cu0.5合金粉粒(熔点为217℃)所组成的混合低熔点微米合金粉粒(其质量比为4:1)，上述混合纳米银粉与混合低熔点微米合金粉粒的质量之比为30:1；并含有将上述粉粒形成膏状的稀释剂、防止银膏中粉末发生团聚的分散剂、封接过程用于还原被焊面氧化层和银膏中金属颗粒氧化层的还原剂。所述稀释剂为质量百分比为1:3:4的正戊烷、丙二醇和醋酸乙酯，所述稀释剂在整个纳米银膏体系中的质量百分比为8％。所述分散剂为质量百分比为1:2:4的聚乙烯酰胺、聚丙烯酸钠和十二烷基硫酸钠，所述分散剂在整个纳米银膏体系中的质量百分比为2.5％。所述还原剂为质量百分比为1:4的草酸和松香酸，所述还原剂在整个纳米银膏体系中的质量百分比为1.2％。
纳米银膏的制备方法，包括如下步骤：
S1、通过化学还原银盐溶液，并采用将银沉积层在100Pa以下的负压环境中干燥的方法分别得到平均粒径为25nm、70nm、1200nm的纳米银粉；
S2、按照锡基焊料的合金成分分别配置好所述的Sn96.5Ag3Cu0.5合金和Sn42Bi57Ag1合金，并将Sn42Bi57Ag1合金和Sn96.5Ag3Cu0.5合金分别通过真空研磨机研磨，得到平均粒径均为20μm的Sn42Bi57Ag1合金粉粒和Sn96.5Ag3Cu0.5合金粉粒；
S3、按照质量百分比为1:3:4的正戊烷、丙二醇和醋酸乙酯，在整个纳米银膏体系中的总质量百分比为8％的配比，配好稀释剂。按照质量百分比为1:2:4的聚乙烯酰胺、聚丙烯酸钠和十二烷基硫酸钠，在整个纳米银膏体系中的总质量百分比为2.5％的配比，配好分散剂。按照质量百分比为1:4的草酸和松香酸，在整个纳米银膏体系中的总质量百分比为1.2％的配比，配好还原剂。
S4、将步骤S1制成的纳米银粉(平均粒径为25nm的纳米银粉、平均粒径为70nm的纳米银粉、平均粒径为1200nm的纳米银粉的质量比为9:5:1)与步骤S2制成的微米合金粉粒(Sn42Bi57Ag1合金粉粒和Sn96.5Ag3Cu0.5合金粉粒的质量比为4:1)按照质量比30:1，加入到步骤S3配好的含有还原剂、分散剂、稀释剂的混合溶剂中，采用磁力搅拌均匀混合，得到混有微米锡基焊料粉粒的纳米银膏。
实施例五
本实施例提供了一种纳米银膏，该纳米银膏中含有平均粒径为15nm的纳米银粉、平均粒径为60nm的纳米银粉、平均粒径为900nm的纳米银粉、平均粒径为1500nm的纳米银粉所组成的混合纳米银粉，其质量比为12:9:5:1；含有平均粒径为50μm的Sn64Bi35Ag1合金粉粒(熔点范围约为139-180℃)、平均粒径为10μm的Sn96Ag2.5Bi1Cu0.5合金粉粒(熔点约为215℃)、平均粒径为2μm的SnSb5合金粉粒(熔点约为240℃)所组成的混合低熔点微米合金粉粒，其质量比为11:5:2；上述混合纳米银粉与混合低熔点微米合金粉粒的质量之比为80:1；并含有将上述粉粒形成膏状的稀释剂、防止银膏中粉末发生团聚的分散剂、封接过程用于还原被焊面氧化层和银膏中金属颗粒氧化层的还原剂。所述稀释剂为质量百分比为1:2:5的正庚烷、丁醇和醋酸乙酯，所述稀释剂在整个纳米银膏体系中的质量百分比为6％。所述分散剂为质量百分比为1:1:2的聚丙烯酸钾、聚丙烯酰胺和十二烷基硫酸钠，所述分散剂在整个纳米银膏体系中的质量百分比为3％。所述还原剂为质量 百分比为1:3:4的乙酸、戊二酸和松香酸，所述还原剂在整个纳米银膏体系中的质量百分比为1.5％。
纳米银膏的制备方法，包括如下步骤：
S1、通过化学还原银盐溶液，并采用将银沉积层在100Pa以下的负压环境中干燥的方法分别得到平均粒径为15nm、60nm、900nm和1500nm的纳米银粉；
S2、按照锡基焊料的合金成分分别配置好所述的Sn64Bi35Ag1合金、Sn96Ag2.5Bi1Cu0.5合金和SnSb5合金，并将其分别通过真空研磨机研磨得到平均粒径为50μm的Sn64Bi35Ag1合金粉粒、平均粒径为10μm的Sn96Ag2.5Bi1Cu0.5合金粉粒、平均粒径为2μm的SnSb5合金粉粒；
S3、按照质量百分比为1:2:5的正庚烷、丁醇和醋酸乙酯，在整个纳米银膏体系中的总质量百分比为6％的配比，配好稀释剂。按照质量百分比为1:1:2的聚丙烯酸钾、聚丙烯酰胺和十二烷基硫酸钠，在整个纳米银膏体系中的总质量百分比为3％的配比，配好分散剂。按照质量百分比为1:3:4的乙酸、戊二酸和松香酸，在整个纳米银膏体系中的总质量百分比为1.5％的配比，配好还原剂。
S4、将步骤S1制成的纳米银粉(平均粒径为15nm的纳米银粉、平均粒径为60nm的纳米银粉、平均粒径为900nm的纳米银粉、平均粒径为1500nm的纳米银粉的质量百分比为12:9:5:1)与步骤S2制成的微米合金粉粒(Sn64Bi35Ag1合金粉粒、Sn96Ag2.5Bi1Cu0.5合金粉粒和SnSb5合金粉粒的质量比为11:5:2)按照80:1的质量比，加入到步骤S3配好的含有还原剂、分散剂、稀释剂的混合溶剂中，采用机械搅拌均匀混合，得到混有微米锡基焊料粉粒的纳米银膏。
为了进一步验证本发明的技术效果，以下对本发明的纳米银膏进行封接试验。其中，封接试验所需用到的检测样品和被封接材料具体为：
检测样品：
本发明实施例五：混有微米锡基焊料粉粒的纳米银膏
对比例一：未加有微米锡基焊料粉粒(其它条件与本发明实施例 五相同)的纳米银膏
被封接材料：厚度为1.5mm，封接面积为10mm*8mm的无氧铜板。
封接方式：通过在两块无氧铜板中间分别夹设0.1mm厚的对比例一的纳米银膏或者本发明实施例五的纳米银膏，且对对比例一的纳米银膏和本发明实施例五的纳米银膏同时进行无额外施加压力的常压回流封接。
以下对封接后的封接层进行性能测试，封接层的性能测试包括封接层孔隙率、剪切强度、热导率，以及封接层进行温度循环冲击后的孔隙率。封接层孔隙率通过超声波扫描仪或X-Ray检测仪来检测，剪切强度通过电子万能试验机来测试，热导率通过激光闪色法导热分析仪来测试。
封接层的孔隙率越小，表明纳米银膏封接后的封接层质量越好，以及封接层进行温度循环冲击后的孔隙率变化越小，表明封接层的退化程度越低，即封接层抗温度冲击的能力越强。封接层的剪切强度越大，表明封接层抗机械冲击的能力越强。封接层的热导率越大，表明封接层将功率器件工作时产生的热量传导出去的能力越强。
(1)实验一：封接层孔隙率和热导率测试
表1封接后的封接层孔隙率和热导率
Figure PCTCN2022073665-appb-000001
Figure PCTCN2022073665-appb-000002
从表1可以看出，封接后，本发明实施例五的纳米银膏比对比例一的纳米银膏的封接层孔隙率平均降低约53.2％((19.74-9.24)/19.74×100％＝53.2％)，热导率提高约35.5％((248-183)/183×100％＝35.5％)。
(2)实验二：封接层剪切强度测试
对实验一中的对比例一的纳米银膏和本发明实施例五的纳米银膏封接后相互对应的五组封接层分别进行剪切强度测试，测试结果如表2所示。
表2封接后的封接层剪切强度
Figure PCTCN2022073665-appb-000003
从表2可以看出，封接后，本发明实施例五的纳米银膏比对比例一的纳米银膏的封接层剪切强度提高约29.2％((35.0-27.1)/27.1×100％＝29.2％)。
(3)实验三：封接层经过温度循环冲击后的孔隙率(退化程度)
对实验一中的对比例一的纳米银膏和本发明实施例五的纳米银膏封接后相互对应的五组封接层分别经过1000次，-40℃-125℃的温度循环冲击后，检测其封接层孔隙率(温度循环冲击后的封接层孔隙率相 较于温度循环冲击前的封接层孔隙率变化较大时，说明退化程度较严重，其中，退化程度＝温度循环冲击后的孔隙率-温度循环冲击前的孔隙率)，测试结果如表3所示。
表3封接后的封接层经温度循环冲击后的退化程度
Figure PCTCN2022073665-appb-000004
从表3可以看出，采用对比例一的纳米银膏和本发明实施例五的纳米银膏封接后的封接层在经过1000次，-40℃-125℃的温度循环冲击后，本发明实施例五的纳米银膏的封接层退化程度明显低于对比例一的纳米银膏的封接层退化程度，本发明实施例五的纳米银膏的封接层退化程度比对比例一的纳米银膏的封接层退化程度要降低约46.7％((3.45-1.84)/3.45×100％＝46.7％)。
为了更进一步验证本发明的技术效果，以下对本发明实施例一的加有不同粒径和不同加入量的微米锡基焊料粉粒的纳米银膏，作为对比例进行封接试验。其中，封接试验所需用到的检测样品和被封接材 料具体为：
检测样品：本发明实施例一的加有不同粒径和不同加入量的微米锡基焊料粉粒的纳米银膏
本发明实施例一：按照纳米银粉与平均粒径为5μm的微米Sn42Bi58粉粒的质量之比为200:1，制成的纳米银膏
对比例二：按照纳米银粉与平均粒径为5μm的微米Sn42Bi58粉粒的质量之比为10:1(其它条件与本发明实施例一相同)，制成的纳米银膏
对比例三：按照纳米银粉与平均粒径为5μm的微米Sn42Bi58粉粒的质量之比为800:1(其它条件与本发明实施例一相同)，制成的纳米银膏
对比例四：按照纳米银粉与平均粒径为250μm的微米Sn42Bi58粉粒的质量之比为200:1(其它条件与本发明实施例一相同)，制成的纳米银膏
被封接材料：厚度为1.5mm，封接面积为10mm*8mm的无氧铜板。
封接方式：通过在两块无氧铜板中间分别夹设0.1mm厚的本发明实施例一、对比例二、对比例三、对比例四的纳米银膏，且对本发明实施例一、对比例二、对比例三、对比例四的纳米银膏同时进行无额外施加压力的常压回流封接。
对封接后的封接层，经过1000次，-40℃-125℃的温度循环冲击后的退化程度进行测试，测试结果如表4所示。
表4封接后的封接层经温度循环冲击后的退化程度
Figure PCTCN2022073665-appb-000005
Figure PCTCN2022073665-appb-000006
从表4可以看出，采用本发明实施例一、对比例二、对比例三、对比例四的纳米银膏封接后的封接层在经过1000次，-40℃-125℃的温度循环冲击后，本发明实施例一的纳米银膏的封接层退化程度明显低于对比例二、对比例三、对比例四的纳米银膏的封接层退化程度，本发明实施例一的纳米银膏的封接层退化程度比对比例二的纳米银膏的封接层退化程度要降低约59.3％((5.77-2.35)/5.77×100％＝59.3％)，比对比例三的纳米银膏的封接层退化程度要降低约31.1％((3.41-2.35)/3.41×100％＝31.1％)，比对比例四的纳米银膏的封接层退化程度要降低约46.6％((4.40-2.35)/4.40×100％＝46.6％)。

Claims (10)

  1. 一种纳米银膏，其特征在于，包括纳米银粉、微米锡基焊料粉粒、还原剂、分散剂、稀释剂。
  2. 根据权利要求1所述的纳米银膏，其特征在于，所述微米锡基焊料粉粒的材质为熔点在120-250℃范围内的锡基合金。
  3. 根据权利要求2所述的纳米银膏，其特征在于，所述微米锡基焊料粉粒的材质为SnBi系列合金、SnBiAg系列合金、SnAg系列合金、SnCu系列合金、SnAgCu系列合金、SnSb系列合金、SnSbCu系列合金、SnSbAg系列合金、SnAgCuBi系列合金、SnAgCuSb系列合金中的至少一种。
  4. 根据权利要求1所述的纳米银膏，其特征在于，
    所述纳米银粉的平均粒径为5-3000nm；
    所述微米锡基焊料粉粒的平均粒径为0.1-100μm。
  5. 根据权利要求4所述的纳米银膏，其特征在于，
    所述纳米银粉的平均粒径为10-1500nm；
    所述微米锡基焊料粉粒的平均粒径为0.5-50μm。
  6. 根据权利要求1所述的纳米银膏，其特征在于，所述纳米银粉为一种平均粒径的纳米银粉或两种以上不同平均粒径的纳米银粉混合体。
  7. 根据权利要求1所述的纳米银膏，其特征在于，所述纳米银粉与所述微米锡基焊料粉粒的质量之比为20-500:1。
  8. 根据权利要求7所述的纳米银膏，其特征在于，所述纳米银粉与所述微米锡基焊料粉粒的质量之比为30-200:1。
  9. 根据权利要求1所述的纳米银膏，其特征在于，
    所述稀释剂为醇类、烃类、酮类、酯类中的至少一种；
    所述稀释剂在体系中的质量百分比为2-8％；
    所述分散剂为聚烃类酰胺、聚烃类酸盐、烷基酸盐中的至少一种；
    所述分散剂在体系中的质量百分比为0.1-3％；
    所述还原剂为有机酸中的至少一种；
    所述还原剂在体系中的质量百分比为0.1-1.5％。
  10. 权利要求1-9任一项所述的纳米银膏的制备方法，其特征在于， 是将所述纳米银粉、所述微米锡基焊料粉粒与所述还原剂、分散剂、稀释剂混合均匀，得到纳米银膏。
PCT/CN2022/073665 2021-04-25 2022-01-25 一种纳米银膏及其制备方法 WO2022227736A1 (zh)

Priority Applications (2)

Application Number Priority Date Filing Date Title
JP2023559032A JP2024512617A (ja) 2021-04-25 2022-01-25 ナノ銀ペースト及びその製造方法
US18/468,587 US20240009731A1 (en) 2021-04-25 2023-09-15 Nano silver paste and preparation method thereof

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202110447478.9A CN113284645B (zh) 2021-04-25 2021-04-25 一种纳米银膏及其制备方法
CN202110447478.9 2021-04-25

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US18/468,587 Continuation US20240009731A1 (en) 2021-04-25 2023-09-15 Nano silver paste and preparation method thereof

Publications (1)

Publication Number Publication Date
WO2022227736A1 true WO2022227736A1 (zh) 2022-11-03

Family

ID=77277342

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2022/073665 WO2022227736A1 (zh) 2021-04-25 2022-01-25 一种纳米银膏及其制备方法

Country Status (4)

Country Link
US (1) US20240009731A1 (zh)
JP (1) JP2024512617A (zh)
CN (1) CN113284645B (zh)
WO (1) WO2022227736A1 (zh)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113284645B (zh) * 2021-04-25 2022-10-11 广州汉源微电子封装材料有限公司 一种纳米银膏及其制备方法
CN114473103A (zh) * 2022-04-19 2022-05-13 合肥阿基米德电子科技有限公司 一种液态金属锡辅助纳米银烧结工艺

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107175433A (zh) * 2017-04-19 2017-09-19 天津大学 一种低温烧结的锡掺杂纳米银焊膏的制备方法
CN109215828A (zh) * 2018-08-22 2019-01-15 湖南省国银新材料有限公司 一种可焊接的低温烘干银浆及其制备方法
WO2019100445A1 (zh) * 2017-11-22 2019-05-31 深圳市福英达工业技术有限公司 微米/纳米颗粒增强型复合焊料及其制备方法
CN110238562A (zh) * 2019-06-28 2019-09-17 华中科技大学 一种微纳米复合金属焊膏制备方法、产品及应用
JP2020097774A (ja) * 2018-12-17 2020-06-25 キョン ドン ウォン コーポレーションＫｙｕｎｇ Ｄｏｎｇ Ｏｎｅ Ｃｏｒｐｏｒａｔｉｏｎ 電力半導体接合用焼結ペースト組成物
CN113284645A (zh) * 2021-04-25 2021-08-20 广州汉源新材料股份有限公司 一种纳米银膏及其制备方法

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH11329072A (ja) * 1998-05-13 1999-11-30 Murata Mfg Co Ltd 導電ペースト及びそれを用いた太陽電池
US20140018482A1 (en) * 2012-03-26 2014-01-16 E I Du Pont De Nemours And Company Polymer thick film solder alloy/metal conductor compositions
US9034417B2 (en) * 2012-08-20 2015-05-19 E I Du Pont De Nemours And Company Photonic sintering of polymer thick film conductor compositions
CN103258584B (zh) * 2013-01-09 2018-04-10 深圳市创智材料科技有限公司 一种导电银浆及其制备方法
KR20170020861A (ko) * 2014-06-23 2017-02-24 알파 어셈블리 솔루션스 인크. 다층 금속 나노 및 미크론 입자
CN104759725B (zh) * 2015-04-17 2016-10-05 哈尔滨工业大学 一种使用微纳米级金属颗粒填充Sn基焊料实现电子组件高温封装的方法
KR101980946B1 (ko) * 2016-11-11 2019-05-21 삼성에스디아이 주식회사 태양전지용 전면 전극 및 이를 포함하는 태양전지
CN107887050A (zh) * 2017-11-27 2018-04-06 钦州学院 一种晶体硅太阳能电池高可焊性正面电极银浆及制备方法
CN108526751B (zh) * 2018-04-26 2019-06-18 深圳市先进连接科技有限公司 一种可用于无压烧结的微纳米混合焊膏及其制备方法
CN109686472B (zh) * 2018-12-29 2020-07-14 广州市儒兴科技开发有限公司 一种单组分hjt电池用低温银浆
CN109979639A (zh) * 2019-02-18 2019-07-05 英鸿纳米科技股份有限公司 一种纳米芯片封装用混合型导电银浆

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107175433A (zh) * 2017-04-19 2017-09-19 天津大学 一种低温烧结的锡掺杂纳米银焊膏的制备方法
WO2019100445A1 (zh) * 2017-11-22 2019-05-31 深圳市福英达工业技术有限公司 微米/纳米颗粒增强型复合焊料及其制备方法
CN109215828A (zh) * 2018-08-22 2019-01-15 湖南省国银新材料有限公司 一种可焊接的低温烘干银浆及其制备方法
JP2020097774A (ja) * 2018-12-17 2020-06-25 キョン ドン ウォン コーポレーションＫｙｕｎｇ Ｄｏｎｇ Ｏｎｅ Ｃｏｒｐｏｒａｔｉｏｎ 電力半導体接合用焼結ペースト組成物
CN110238562A (zh) * 2019-06-28 2019-09-17 华中科技大学 一种微纳米复合金属焊膏制备方法、产品及应用
CN113284645A (zh) * 2021-04-25 2021-08-20 广州汉源新材料股份有限公司 一种纳米银膏及其制备方法

Also Published As

Publication number Publication date
CN113284645A (zh) 2021-08-20
US20240009731A1 (en) 2024-01-11
CN113284645B (zh) 2022-10-11
JP2024512617A (ja) 2024-03-19

Similar Documents

Publication Publication Date Title
WO2022227736A1 (zh) 一种纳米银膏及其制备方法
TWI651149B (zh) 金屬接合用組成物
EP3217424B1 (en) Electroconductive assembly for electronic component, semiconductor device in which said assembly is used, and method for manufacturing electroconductive assembly
US8491998B2 (en) Composite nanometal paste of two-metallic-component type, bonding method, and electronic part
TWI417399B (zh) 具有奈米微粒之複合無鉛焊錫合金組成物
CN110153589B (zh) 一种铟基钎料及其制备方法
KR102243472B1 (ko) 전력반도체 접합용 소결 페이스트 조성물
TW201942372A (zh) 銅糊、接合方法以及接合體之製造方法
WO2023109597A1 (zh) 纳米铜焊膏及其在芯片封装互连结构中的应用
Liu et al. Microstructural evolution, fracture behavior and bonding mechanisms study of copper sintering on bare DBC substrate for SiC power electronics packaging
Gao et al. Effects of phenolic resin addition on the electrical conductivity and mechanical strength of nano-copper paste formed Cu-Cu joints
CN104588905A (zh) Ag-Cu-Ti/Sn纳米颗粒焊膏及其制备方法
CN112475662A (zh) 纳米银焊膏及其制备方法和在芯片封装互连结构中的应用
CN112351598A (zh) 一种铜颗粒焊膏及其制备方法以及烧结方法
CN112658529B (zh) 一种焊膏及其应用
Satoh et al. Silver adhesive layer for enhanced pressure-free bonding using copper nanoparticles
Hu et al. Rapid formation of Cu–Cu joints with high shear strength using multiple-flocculated Ag nanoparticle paste
WO2022061834A1 (zh) 一种铜颗粒焊膏及其制备方法以及烧结方法
Gao et al. A Cu-Cu Bonding method using preoxidized Cu microparticles under formic acid atmosphere
CN114473110B (zh) 一种抗电迁移抗氧化的焊膏及其应用
WO2020196299A1 (ja) 金属ペースト、接合方法及び接合体の製造方法
CN111916344B (zh) 一种基于石墨烯/锡改性的铜纳米颗粒的铜-铜低温键合方法
Maeda et al. Low-temperature metal–metal bonding process using leaf-like aggregates composed of CuO nanoparticles
CN116408568A (zh) 一种焊膏和组合件
CN117984010A (zh) 一种金属焊膏及其封装方法和应用

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 22794217

Country of ref document: EP

Kind code of ref document: A1

WWE Wipo information: entry into national phase

Ref document number: 2023559032

Country of ref document: JP

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 22794217

Country of ref document: EP

Kind code of ref document: A1